A standard alcove bathtub is 60 inches long, 30 to 32 inches wide and 14 to 18 inches tall, and holds 8.5 to 11.3 inches of water at the overflow. That number is easy to find and it is not the number that decides your project. The measurements that actually stop bathroom remodels are the clearance around the tub, the narrowest point on the path from your front door to the bathroom, and the load the filled tub puts on the floor.
Quick answer: standard bathtub dimensions
For a standard wall-to-wall alcove bathtub, plan on 60 inches long, 30 to 32 inches wide, and 14 to 20 inches of interior depth. Freestanding tubs run longer and deeper: 55 to 75 inches long, 26 to 47 inches wide, and 21 to 31 inches tall on the outside. Those are the numbers to start from, and every one of them has a consequence attached to it.
| The measurement | Typical figure | What it actually decides |
|---|---|---|
| Length | 60 in standard, 55 to 75 in freestanding | Whether the tub fits the wall you have picked, and whether it clears your hallway corner |
| Width | 30 to 32 in standard, up to 47 in freestanding | How much floor the tub eats, and how much is left for the vanity and door swing |
| Height | 15 to 20 in alcove, 21 to 31 in freestanding | Your step-over height, and the clear opening the tub needs to get through a door on edge |
| Water depth | 8.5 to 12 in alcove, about 13 to 17 in in our freestanding tubs, about 21 to 23 in in Japanese-style soakers | Whether the water covers your shoulders when you lie back |
| Capacity | 62 to 140 gallons | Fill time, and whether your water heater can deliver a hot bath in one go |
| Empty weight | 30 to 550 lbs depending on material | How many people it takes to carry, and whether the floor needs a look |
If you only take one thing from this guide: a tub that fits the floor plan can still fail, and it is almost never the length that caused it.
Bathtub sizes by type, length, width and height
Bathtub dimensions vary more by installation type than by brand. The table below gives the typical range for each style along with the thing that range costs you, because a dimension without a consequence is just trivia.
| Type of bathtub | Length | Width | Height | What the size means for you |
|---|---|---|---|---|
| Small alcove | 54 in | 30 in | 15 in | Fits a 54 in rough opening. Most adults cannot stretch out |
| Alcove | 60 in | 32 in | 18 in | The default. Three walls do the supporting, so no clearance needed |
| Drop-in | 45 to 72 in | 30 to 32 in | 14 to 20 in | Add 6 to 12 in of deck on every exposed side to the footprint |
| Undermount | 45 to 72 in | 30 to 36 in | 14 to 20 in | Same as drop-in, plus the thickness of the stone or tile deck |
| Oval | 60 in | 41 in | 24 in | Wide. Check it against your vanity run before you commit |
| Whirlpool | 60 in | 32 to 36 in | 18 to 23 in | Needs an access panel for the pump, which needs its own clearance |
| Corner | 60 x 60 in | up to 72 x 72 in | 20 to 22 in | Eats a whole corner. Only works in rooms over about 8 x 8 ft |
| Freestanding | 55 to 75 in | 26 to 47 in | 21 to 31 in | Needs open floor on all four sides, which is the real cost |
| Japanese soaking | 47 to 60 in | 27 to 55 in | 27 to 31 in | Short footprint, tall sides. Deep soak in a small room |
| Clawfoot | 54 to 72 in | 30 to 40 in | 24 to 30 in | Feet concentrate the whole load onto four small points |
| Garden | 60 to 70 in | 42 to 50 in | 24 to 30 in | Wide and deep. Check your water heater before ordering |
| Walk-in | 48 to 60 in | 28 to 32 in | 36 to 40 in | Tall sides need headroom, and you sit while it fills and drains |
Our own range runs from 47.2 inches at the shortest to 74.8 inches at the longest, so if you are shopping by size the fastest route is to start from a length: 60 inch freestanding tubs for standard rooms, 72 inch freestanding tubs for a primary suite, or the small tub collection when the room is the constraint. If you want the whole range in one place, the full freestanding bathtub collection lists exterior dimensions and weight on every product page.
What are bathtub dimensions in feet, centimeters and meters?
A standard 60 by 30 inch bathtub is 5 by 2.5 feet, 152 by 76 centimeters, or 1.52 by 0.76 meters. Here are the common lengths in all four units so you can check a spec sheet against a tape measure in whichever system your contractor uses.
| Inches | Feet | Centimeters | Meters |
|---|---|---|---|
| 48 in | 4 ft | 122 cm | 1.22 m |
| 54 in | 4.5 ft | 137 cm | 1.37 m |
| 60 in | 5 ft | 152 cm | 1.52 m |
| 66 in | 5.5 ft | 168 cm | 1.68 m |
| 72 in | 6 ft | 183 cm | 1.83 m |
| 30 in (width) | 2.5 ft | 76 cm | 0.76 m |
| 32 in (width) | 2.67 ft | 81 cm | 0.81 m |
How much clearance do you need around a bathtub?
You need at least 30 inches of clear floor running the full length of the tub on the side you step in from, and 6 to 12 inches between the tub and any wall or fixture on the other three sides. Those are two different rules answering two different questions, and they get mixed up constantly: apply the 30 inch entry figure to all four sides and a perfectly workable bathroom looks impossible on paper.
How much space do you need in front of a bathtub?
Thirty inches, measured from the tub rim outward and running the entire length of the tub. That figure comes from the accessibility standards rather than a comfort guideline: the US Access Board's guidance on ADA section 607.2 requires clearance in front of a bathtub to extend the length of the tub and be 30 inches wide minimum, with an extra 12 inches beyond the head-end wall where the tub has a permanent seat. You are not legally bound by it in a private home, but it is the only sourced number in this category. Below roughly 24 inches the gap stops reading as a walkway and starts reading as a squeeze, which is why 30 inches is worth treating as a target rather than a minimum.
How much space goes behind and beside a freestanding tub?
Six to twelve inches between the tub and any wall or fixture. That gap is not about comfort, it is about maintenance: below roughly 6 inches you cannot get a hand and a cloth down the back of the tub, and the dust and water that collect there turn into a permanent job.
The useful way to think about it is that the good answers are at the two ends, not in the middle. Either leave enough room to reach behind the tub properly, or eliminate the gap entirely with a back-to-wall model designed to sit flush. A two to four inch gap is the worst of both: too narrow to clean, too wide to ignore, and it collects everything. If your room cannot spare the clearance, a back-to-wall freestanding tub is the honest solution, and pushing a standard freestanding tub against a wall is not, because it has no flange on that side and water will get behind it.
If your faucet is a floor-mounted filler rather than a rim mount, the gap on that end needs to clear the supply line and the escutcheon too, which usually means budgeting toward the 12 inch end. Our freestanding tub fillers list their footprint on each product page.
Does the bathroom door swing count against the clearance?
Yes, and it is the clearance people forget. A standard 30 inch interior door sweeps a quarter circle roughly 30 inches deep into the room, and that arc cannot overlap the 30 inch entry zone in front of your tub or you will be squeezing past a door edge every time you get out. If the plan is tight, a door that swings out into the hallway or a pocket door buys back the entire arc, and it is far cheaper than shortening the tub.
What size bathtub fits your bathroom?
Room size sets the tub length far more strictly than most size charts admit, because the tub is never the only thing in the room. The three plans below are drawn to one shared scale with a toilet, a vanity and a door swing placed, which is the only way to see where the space actually runs out.
| Bathroom size | Tub that fits | The constraint |
|---|---|---|
| 5 x 7 ft | 54 in alcove | A 60 in tub leaves no run for the vanity |
| 5 x 8 ft | 60 in alcove | The room is literally built around the 60 in tub. No freestanding option |
| 6 x 8 ft | 60 in alcove, or 55 to 60 in freestanding on the short wall | Freestanding works only if the toilet moves to the long wall |
| 6 x 9 ft | 60 to 63 in freestanding | Six inches at each end, which is the minimum that stays cleanable |
| 8 x 10 ft | 72 in freestanding, or a 60 x 60 corner tub | Nothing, at this size the tub choice is yours |
What size bathtub fits a 5 by 8 bathroom?
A 60 inch alcove tub, and realistically nothing else. The 5 by 8 bathroom is 60 by 96 inches, and the 60 inch short wall exists because the 60 inch tub does: American bathrooms were laid out around the fixture. A freestanding tub in that room would need 72 inches of wall to keep 6 inches at each end, so the only way to get one into a 5 by 8 is to steal space from an adjoining room. If you are working with this footprint, our guide to bathtubs for small spaces covers the layouts that do work.
What is the smallest bathtub size that still works?
Forty-eight inches is the practical floor for a conventional tub, and it is short enough that most adults sit rather than recline. The better move in a small room is not a shorter tub but a deeper one: a Japanese-style soaker gives up length and takes it back in height, so you get a full-shoulder soak out of a 47 inch footprint. The two shortest tubs we make are both this shape at 47.2 inches long and 27.6 to 30.7 inches tall, which is why the Japanese soaking tub collection is where we point people whose room is the constraint but who still want to be covered by water.
What size bathtub do you need for a 6 foot person?
Sixty-six inches or longer, measured on the interior rather than the exterior. A 72 inch exterior tub gives roughly 60 to 64 inches of interior bathing length once you subtract the wall thickness and the slope of the backrest at each end, which is comfortable for someone at 6 feet. At 60 inches exterior you are down to about 50 inches inside, and a six-footer bathes with their knees up. If height is the reason you are buying, start in large tubs or extra large tubs and read the interior figures, not the headline length.
What size bathtub works for two adults?
Plan on 70 inches of length and at least 35 inches of width, and expect the capacity to roughly double. Our largest tub is 74.8 by 47.2 inches and holds 140 gallons, against 62 to 80 gallons for a single-bather tub, and that gallon figure is the part people underestimate: it is a real question of whether your water heater can fill it hot. The two person soaking tub collection is the size-filtered version of this decision, and we go deeper on it in our guide to what size tub two adults actually need.
Will the tub actually reach the bathroom?
This is the measurement nobody publishes and the one that cancels orders. A tub that fits the bathroom perfectly is useless if it cannot get down the hallway, and the two numbers that decide it are the clear width of your narrowest doorway and the geometry of your tightest corner. Neither of them is the tub's length.
What doorway width does a bathtub need?
Between 21 and 25 inches of clear opening for most freestanding tubs, because a tub goes through a door tipped onto its side, and the dimension that has to clear is the tub's height. Across our own 27 tub range that figure runs from 21.2 inches to 31.3 inches, and 24 of the 27 need 26 inches or less. A standard 30 inch interior door gives roughly 27.5 to 28 inches of clear opening once you account for the stop and the open door slab, so almost everything clears it.
The exceptions are the ones worth knowing about, and they are counterintuitive. The two tubs in our range that will not clear a standard 30 inch door are both deep Japanese-style soakers at 27.6 and 31.3 inches tall. Those are precisely the tubs people buy for small bathrooms, which are precisely the houses most likely to have narrow doors. If you are buying a tall soaker, measure the door before you measure the room.
How do you get a bathtub around a hallway corner?
You turn it up on end, and if you cannot, the limit in a typical 36 by 36 inch hallway corner is about 58 inches of tub length. That figure assumes a rigid tub kept flat on the floor, and 24 of our 27 tubs are longer than it. In practice delivery crews beat the corner by tilting the tub vertically and pivoting it, which turns a floor-plan problem into a ceiling-height problem. That is why the measurement that matters at a corner is usually headroom, not hallway width.
Measure the narrowest point on the whole route, not the average. One 32 inch hallway pinch between the front door and the bathroom sets the limit for the entire delivery, and finding it after the freight truck arrives is an expensive way to learn it. Our guide on how to move a bathtub walks the full route survey.
Can you carry a bathtub up a staircase?
Yes, with enough people and the right equipment, but the number of people scales with the material and not the size. A fiberglass tub at 30 to 70 pounds is a two-person carry. A stone resin tub at 240 to 550 pounds empty needs four to six people or a powered stair-climbing dolly, and the person at the bottom of the flight carries a disproportionate share of that weight. The half-landing turn on a switchback staircase is usually tighter than any doorway in the house, so measure it.
| Measure this | Write it here | It fails if |
|---|---|---|
| Narrowest doorway, clear opening with the door open | ______ in | Less than the tub's height |
| Tightest 90 degree corner, both hallway widths | ______ x ______ in | Both under 36 in and the tub is over 58 in |
| Lowest ceiling or stair soffit on the route | ______ in | Less than the tub's length plus 6 in |
| Stair half-landing, both directions | ______ x ______ in | Smaller than the tightest hallway corner |
| Bathroom door, clear opening | ______ in | Less than the tub's height |
Built in tub dimensions and rough in measurements
A built-in tub is 60 inches long by 30 to 32 inches wide by 14 to 20 inches deep, and the rough opening it drops into needs to be measured after the walls are finished, not before. "Built in" covers alcove, drop-in and undermount tubs, and all three share the same problem: the number on the box is the tub, and the number that matters is the hole.
Will a 60 inch tub fit exactly in a 60 inch space?
No, and the reverse trips up even more people: if your tiled alcove measures 58 inches, you almost certainly still have a 60 inch opening. A "60 inch alcove" is a stud-to-stud dimension. Add half-inch backer board and tile on both walls and the visible, finished opening comes out somewhere between 57.75 and 59 inches. The tub still fits, because the tub goes in first and the tile comes down over its flange afterwards.
This one misunderstanding causes more wrong purchases than any other measurement in bathroom remodeling. Homeowners measure tile to tile, read 58.5 inches, and buy a 54 inch tub they will regret, or worse, a contractor gouges the studs to force a 60 inch tub into a finished 59 inch gap. Neither is necessary. Before you size down, pull a piece of trim or check the framing: the question is what the studs measure, not what the tile measures.
What goes wrong in a 60 by 30 alcove?
Five things, in roughly the order they cause trouble.
- The opening was measured after tile. See above. This is the big one, and the fix is free.
- The alcove is not square. Older houses settle, and an alcove that measures 60 inches at the front and 59.25 inches at the back wall will not accept a 60 inch tub no matter how the tile is handled. Measure at the front, the middle and the back, at more than one height, and use the smallest number. Sloped and out-of-plumb walls defeat a single reading.
- The opening is too big. Less common and just as annoying. A 63 inch rough opening left by a removed shower gives a 60 inch tub a three inch gap that has to be framed out or trimmed. Measure before you order, not after.
- The drain is on the wrong end. Alcove tubs are handed: a left-drain tub and a right-drain tub are not interchangeable, and the rough-in is in the floor. Getting this wrong means opening the ceiling below to move the waste line.
- The replacement is a different material. Swapping a cast iron tub for an acrylic one of the same nominal size changes the wall thickness, the flange height and the apron profile. The new tub often sits lower, and the existing tile no longer overlaps it correctly. New floor tile compounds it by raising the finished height under the apron.
If you are replacing rather than remodeling, our guide to removing and replacing a bathtub covers the sequence, and what an alcove tub is explains the flange detail that makes or breaks the fit.
How deep is a bathtub, and how much depth do you actually need?
Standard alcove bathtubs hold 8.5 to 11.3 inches of water, measured from the bottom of the tub to the overflow drain. Freestanding soakers go deeper: most of our freestanding models hold about 13 to 17 inches, and Japanese-style soakers reach about 21 to 23 inches. Depth is the dimension most people get wrong, because the number on the spec sheet is the exterior height and the number that matters is how far up your body the water comes.
What is standard bathtub water depth?
About 8.5 to 11.3 inches in a standard alcove tub, which covers your legs and hips and leaves your chest and shoulders in the air. If you want to be submerged to the shoulders you need water at 18 to 22 inches, and since the overflow sets the waterline well below the rim, that means an exterior height in the mid-twenties or higher.
Here is the trap, and it is worth being blunt about it because our industry is not. The height on a spec sheet is the outside of the tub. The water stops at the overflow, which sits several inches below the rim, and then your body displaces some of what is left. Plenty of tubs sold as deep soakers put 9 to 11 inches of water around you. That is the gap between the number people buy and the bath they get, and it is why homeowners end up flipping their overflow plates upside down to steal a couple more inches. We would rather you avoided the DIY plumbing: ask for the water depth at the overflow before you buy, from us or anyone else, and treat exterior height as a proxy only. As a rough rule, a tub under about 20 inches tall is a bathing tub, not a soaking tub. Our guide to extra deep soaking tubs works through where that line sits.
How tall is a bathtub from the floor?
Alcove tubs sit 15 to 20 inches off the floor, freestanding tubs 21 to 31 inches, and walk-in tubs 36 to 40 inches. That figure is your step-over height, and it is a safety number as much as a comfort one. The CDC's national injury survey found roughly 234,000 nonfatal bathroom injuries treated in US emergency departments in a single year among people aged 15 and over, with 37.3 percent occurring while bathing, showering or getting out of the tub, and around 80 percent of all bathroom injuries caused by falls, according to the CDC's report on nonfatal bathroom injuries. If anyone in the house is over 70 or has limited mobility, a 30 inch step-over on a deep soaker is a real decision, not a styling one.
How much weight does a full bathtub put on your floor?
A filled tub with a bather in it concentrates roughly 63 to 126 pounds per square foot onto its footprint, against the 40 pounds per square foot of uniform live load that residential floors are designed to carry. That sounds alarming and usually is not, but it is worth understanding properly instead of guessing.
How much does a bathtub weigh empty?
Anywhere from 30 to 900 pounds, entirely depending on material. These are the published figures for each material, and the consequence column is the part that matters on install day.
| Material | Empty weight | What that means on delivery day |
|---|---|---|
| Fiberglass | 30 to 70 lbs | Two people, no equipment |
| Acrylic | 70 to 100 lbs | Two people, awkward rather than heavy |
| Enameled steel | 70 to 150 lbs | Two to three people |
| Stone resin | 240 to 550 lbs (our range) | Four to six people, or a powered dolly on stairs |
| Cast iron | 300 to 500+ lbs | Four or more, and it will not survive being dropped |
How much does a full bathtub weigh?
Between about 950 and 1,900 pounds once you add the water and the person. Water weighs 8.34 pounds per gallon, so a 67 gallon tub is carrying 559 pounds of water on its own. Running the arithmetic across our published range: the lightest combination is roughly 957 pounds and the heaviest, a 140 gallon two-person tub, comes to about 1,899 pounds.
Those figures are a deliberate worst case. A tub filled to the overflow cannot also hold a person, because the person displaces the water and the surplus goes down the drain. Real loaded weight sits below the numbers above, so treat them as the ceiling rather than the expectation.
Here is the part that surprises people. The water is the load, not the tub. On a typical 63 inch stone resin tub the breakdown is 357 pounds of tub, 559 pounds of water and roughly 180 pounds of bather. Swap that tub for a 90 pound acrylic of the same capacity and the total drops by about a quarter, not by an order of magnitude. "Stone resin is too heavy for upstairs" is a common objection, and the arithmetic does not support it: any tub of that capacity puts most of the same load on the same joists.
Do you need to reinforce the floor for a soaking tub?
Usually not, but the honest answer is that it depends on your joists and nobody can tell you from a spec sheet. The 40 pounds per square foot figure in the International Residential Code's live load table R301.5 is a uniform design load for rooms other than sleeping rooms, and a bathtub is not a uniform load. Floors are built with margin, and load spreads across multiple joists rather than sitting on one. So exceeding 40 psf over a tub footprint is normal and not automatically a problem.
What genuinely warrants a structural opinion: a tub over about 100 gallons, an upper floor in a house built before about 1950, joists spanning more than roughly 14 feet, a clawfoot tub that puts the entire load on four small feet, or any visible bounce in the existing floor. In those cases the cost of an hour of a structural engineer's time is trivial against the cost of being wrong. For everything else, a 60 to 72 inch soaking tub on a sound modern floor is a routine installation.
How the material changes the dimensions that matter
Two tubs with identical exterior dimensions can give you noticeably different baths, because wall thickness, heat retention and weight all vary by material. Exterior length is the number on the box. Interior length is the number you lie in.
Cast iron walls are thick, which is why a 60 inch cast iron tub gives you less interior room than a 60 inch acrylic one. Acrylic walls are thin and flex, which is why acrylic tubs are light and why they cool fast. Stone resin sits in between on thickness and at the top on density: we cast ours from 65 percent calcium carbonate and 35 percent resin, using finely ground dolomite, with a gelcoat surface layer. That density is what holds heat, and it is also what puts our tubs at 240 to 550 pounds empty.
On heat retention the mechanism is density: a thick mineral-filled wall pulls heat out of bath water far more slowly than a thin sheet of flexing acrylic. Badeloft states this qualitatively rather than as a tested number, so treat any specific "stays warm X minutes longer" figure you find online with suspicion unless it names a test method and a starting temperature. If you are choosing between materials rather than sizes, our stone resin versus acrylic comparison puts the two side by side, and the full bathtub materials guide covers the rest.
Bathtub volume and fill time
A standard bathtub holds around 80 gallons and fills in 5 to 7 minutes. Freestanding tubs hold 62 to 140 gallons depending on size and take 7 to 15 minutes, and that range is wide enough that it changes which tub you should buy.
The constraint is your water heater, not your tap. Most residential water heaters hold 40 to 50 gallons, and you cannot draw all of it as hot water: a 40 gallon heater delivers roughly a 55 to 65 gallon bath once it mixes with cold. That is fine for a 62 gallon tub filled to the overflow. It is not fine for a 140 gallon two-person tub, which needs either a larger tank or an on-demand system. Check this before you order, because it is the one constraint you cannot solve after the tub is installed.
Volume also sets the maintenance rhythm and the water bill. A 120 gallon bath is not a nightly habit for most households, and we would rather say that plainly than sell you a tub you use twice a year. Our guide to how many gallons a bathtub holds has the full capacity breakdown by type.
What to measure before you buy a bathtub
Seven numbers decide whether a given tub works in your house. Take all seven before you order, not after.
- The wall or alcove, at three points. Front, middle and back. Use the smallest figure, and take it after tile if the tile is already on.
- The clear floor on the entry side. You want 30 inches running the length of the tub. Under 24 and the room will feel wrong.
- The gap at the back and both ends. Six to twelve inches for a freestanding tub. Zero for an alcove tub, which is the point of an alcove tub.
- The door swing. Draw the arc on the floor plan. If it crosses the entry zone, change the door, not the tub.
- The narrowest doorway on the delivery route. Compare it to the tub's height, not its width.
- The tightest corner and the lowest headroom. Both hallway widths at the corner, and the ceiling or stair soffit above it.
- The drain position. Which end, and how far from the wall. This is the one that opens ceilings when it is wrong.
If any of the first four fail, change the tub. If any of the last three fail, change the route or the delivery method, because the tub is usually not the thing that has to give. We send free full-size paper templates and material samples for exactly this reason: taping the actual footprint to your floor answers most of these questions in ten minutes, and a template costs nothing to be wrong about.
Two installation details that are not measurements but cause the same kind of expensive surprise. A freestanding tub has to be anchored to the floor, not just set on it. An unanchored tub shifts when you lean on the rim, and the movement works the waste connection loose, which is how a new bathroom ends up smelling of drains. And any tub with a tiled surround should be caulked while it is full of water, because a tub deflects under load and a bead laid on an empty tub tears the first time someone takes a bath.
FAQs
What is the standard size of a bathtub?
Sixty inches long, 30 to 32 inches wide, and 14 to 20 inches of interior depth. That is the standard alcove tub, which is the most common bathtub in American homes because the standard 5 by 8 foot bathroom was laid out around it.
Are all bathtubs the same size?
No. Alcove tubs cluster tightly around 60 by 30 inches because they have to fit a framed opening, but freestanding tubs range from 47 to 75 inches long and 26 to 47 inches wide. Two tubs with the same exterior length can also give very different interior space depending on wall thickness.
Is a 54 inch bathtub too small?
For an adult who wants to stretch out, yes. A 54 inch tub gives roughly 44 to 46 inches of interior length, which means sitting upright with knees bent rather than reclining. It is a reasonable choice for a guest bathroom, a children's bathroom, or a room where 60 inches genuinely does not fit.
How much space do you need around a freestanding bathtub?
Thirty inches of clear floor on the side you step in from, running the full length of the tub, and 6 to 12 inches between the tub and any wall or fixture on the other sides. The 6 inch minimum is about being able to clean behind the tub, not about looks.
Will a 60 inch tub fit in a 60 inch space?
If your 60 inches is a tiled, finished measurement, you are measuring the wrong thing. A 60 inch alcove is a stud-to-stud dimension, and backer board plus tile brings the visible opening down to roughly 57.75 to 59 inches. The tub goes in against the studs first and the tile comes down over its flange, so a 60 inch tub still fits. Check the framing before you size down.
How much does a full bathtub weigh?
Roughly 950 to 1,900 pounds with water and a bather. Water alone is 8.34 pounds per gallon, so a 67 gallon tub carries 559 pounds of water. The water, not the tub material, is the majority of that load in almost every case.
What size bathtub do I need for a 6 foot person?
Sixty-six inches of exterior length at minimum, and 72 inches is more comfortable. A 72 inch tub gives roughly 60 to 64 inches of interior bathing length once you subtract wall thickness and the backrest slope, which fits someone at 6 feet without their knees coming up.
References
- US Access Board. ADA Accessibility Standards, Chapter 6: Plumbing Elements and Facilities (Section 607 Bathtubs). https://www.access-board.gov/ada/chapter/ch06/
- International Code Council. 2021 International Residential Code, Section R301.5 Live Load (Table R301.5). https://codes.iccsafe.org/s/IRC2021P2/chapter-3-building-planning/IRC2021P2-Pt03-Ch03-SecR301.5
- Centers for Disease Control and Prevention. Nonfatal Bathroom Injuries Among Persons Aged 15 Years and Over, United States, 2008. MMWR, Vol. 60, No. 22, June 10, 2011. https://www.cdc.gov/mmwr/pdf/wk/mm6022.pdf