Toilet dimensions

Toilet dimensions chart

Toilets have no single standard size, but they cluster tightly. Here are seven models from four makers. Depth is front to back, width is the widest point and height runs from the floor to the top of the tank lid.

All seven are built for a 12 in rough-in. Sources: Kohler spec sheets for the K-3987, K-3810 and K-3999, checked against Build.com and Ferguson spec tables (K-3987, K-3810, K-3999). Gerber spec sheets for the Viper GLF21551 and Maxwell MX-21-418. American Standard Cadet 3 spec sheet and Ferguson listing. TOTO's Drake spec sheet gives only the rough-in, so the Drake's outside sizes are from Build.com's spec table.

Across these seven, depth runs from 27 1/8 to 30¼ in (69 to 77 cm), width from 15¾ to 18¾ in (40 to 48 cm) and height from 28 3/16 to 31¼ in (72 to 79 cm). The middle of the pack is about 28 × 17½ × 30 in (71 × 44 × 76 cm). If you plan for a toilet 30 in deep and 19 in wide, almost any standard floor-mounted model will fit.

Toilet size, part by part

Depth decides whether the door clears and how much room is left in front. Width decides how close the toilet can sit to a vanity or tub. Height decides what fits above the tank.

Depth: front to back

Depth is measured from the finished wall to the front of the bowl. Floor-mounted toilets run about 27 to 30 in (69 to 76 cm). Bowl shape drives most of the difference: Kohler's round Wellworth is 27¾ in deep and its elongated Highline is 29¾ in, on the same 12 in rough-in (K-3987 and K-3999 spec sheets). A "compact elongated" bowl such as the Santa Rosa gets the longer seat into 27¾ in.

Width: tank and bowl

The width a maker lists is the widest point of the toilet, which on a two-piece model is usually the tank. In the chart that is 15¾ to 18¾ in (40 to 48 cm). Width rarely decides whether a toilet fits. The code wants 15 in from the toilet's centerline to each side, a 30 in (76 cm) wide space, which is wider than any toilet in the chart.

Height: tank top and seat

Two-piece toilets reach 29 to 31¼ in (74 to 79 cm) at the tank lid. One-piece models sit lower: the Santa Rosa is 28 3/16 in (72 cm) (Ferguson spec table). Check that height under a shelf or cabinet, and leave room to lift the tank lid off.

Standard vs comfort height

A standard-height bowl sits about 2 in lower than a comfort-height one. Kohler's standard-height Wellworth K-3987 is 14½ in (37 cm) to the rim (Build.com spec table). Comfort-height bowls raise the rim to about 16 to 16½ in (41 to 42 cm). Makers give them their own names: Comfort Height (Kohler), Universal Height (TOTO), Right Height (American Standard) and ErgoHeight (Gerber).

The seat adds a little. American Standard lists its Cadet 3 Right Height bowl at 16½ in to the rim and 17 in (43 cm) with the seat on (American Standard product page).

The ADA Standards set the seat height for accessible toilets at 17 to 19 in (43 to 48 cm), measured to the top of the seat (ADA 604.4). Inside a home, the same section allows 15 to 19 in (38 to 48 cm) in residential dwelling units. That is why "ADA height" and "comfort height" are often used for the same toilets.

Comfort height suits most adults, taller people and anyone who finds it hard to stand up from a low seat. A standard bowl can suit children and shorter adults, whose feet stay flat on the floor. See toilet height for the full comparison.

Round vs elongated bowls

An elongated bowl is about 2 in longer than a round one. Bemis, the seat maker, measures from the center of the seat mounting holes to the front of the bowl: typically 16½ in (42 cm) for round and 18½ in (47 cm) for elongated (Bemis seat size guide, PlumbersStock). Both shapes use seat holes 5½ in (14 cm) apart (Kohler spec sheet).

Those 2 in come out of the walkway in front of the toilet. Elongated bowls are roomier to sit on; round bowls save space in a small powder room. A compact elongated bowl gives you the elongated seat at round-bowl depth.

One-piece, two-piece and wall-hung toilets

Two-piece toilets have a separate tank bolted onto the bowl. They are the most common type and the tallest, 29 to 31¼ in in the chart. You can carry the tank and bowl in separately, and replace either one.

One-piece toilets cast the tank and bowl as a single piece of china. With no joint between tank and bowl, there is one less seam to clean and one less gasket to leak. They tend to be lower and more compact: Kohler's one-piece Santa Rosa is 28 3/16 in tall and 27¾ in deep with an elongated, comfort-height bowl.

Wall-hung toilets hang the bowl on the wall and hide the tank in the wall cavity on a steel carrier. Kohler's Veil wall-hung bowl (now discontinued) projects 21 in (53 cm) from the finished wall (Kohler spec sheet, Ferguson). That is 6¾ to 8¾ in less than the floor-mounted Kohlers in the chart. The carriers come for 2×4 and 2×6 walls, and the rim height is set by where the carrier holds the bowl, not by the china.

Rough-in: 12 in, 10 in and 14 in

The rough-in is the distance from the finished wall to the center of the drain, measured to the center of the floor flange's mounting holes (American Standard). Kohler calls 12 in (30.5 cm) the standard rough-in (K-3999 spec sheet), and every toilet in the chart above is built for it.

Older and tighter bathrooms may have 10 in or 14 in. Makers sell versions for both: TOTO makes the Drake in a 10 in rough-in (TOTO spec sheet), Gerber makes the Maxwell in 10 in (Gerber spec sheet) and the Viper in 14 in (The Granite Group listing). A 12 in toilet on a 14 in rough-in leaves a 2 in gap behind the tank. A 12 in toilet will not fit a 10 in rough-in at all, because the tank hits the wall. Our toilet rough-in guide shows how to measure and what to do with an odd size.

Toilet clearances: code minimum vs recommended

The International Residential Code sets the minimum space around a toilet in R307.1 and its Figure R307.1, with the same numbers written out in P2705.1. The center of the toilet must be at least 15 in (38 cm) from any side wall, partition or vanity, at least 30 in (76 cm) center to center from the next fixture, and there must be at least 21 in (53 cm) of clear space in front of it to any wall, fixture or door (IRC chapter 3; P2705.1 as adopted in Oklahoma's code). The International Plumbing Code uses the same 15, 30 and 21 in (ICC, IPC 405.3.1).

Those are minimums. The National Kitchen and Bath Association recommends 18 in (46 cm) from the centerline to any fixture or wall and 30 in (76 cm) of clear floor in front (NKBA Bath Planning Guidelines, Supply House Times). For an accessible toilet, the ADA Standards put the centerline 16 to 18 in (41 to 46 cm) from the side wall and ask for a clear space 60 in (152 cm) wide and 56 in (142 cm) deep around it (ADA 604.2 and 604.3.1).

Sources: NKBA Bath Planning Guidelines (Guidelines 4, 20 and 21, which also list the code figures), ICC, ADA chapter 6. The 60 in toilet room width for wheelchair users is NKBA's figure, and matches the ADA 60 in clear width.

The ADA numbers cover public buildings, not most private homes, but they are the yardstick for an accessible bathroom. The paper holder goes 7 to 9 in in front of the bowl (ADA 604.7); see toilet paper holder height, toilet clearance and ADA bathroom dimensions.

How much space a toilet needs in a bathroom plan

Add the toilet's depth to the clearance in front, and the side clearances to each other. With a 28 to 30 in deep toilet:

• Code minimum: a strip 30 in (76 cm) wide and about 49 to 51 in (124 to 130 cm) from the back wall to the nearest wall, fixture or door.
• NKBA recommended: 36 in (91 cm) wide and about 58 to 60 in (147 to 152 cm) deep.
• Separate toilet room: at least 30 × 60 in (76 × 152 cm) by code, 36 × 66 in (91 × 168 cm) recommended, measured inside the walls (NKBA Guideline 21).
• Accessible: a clear space 60 in wide and 56 in deep from the back wall, with the centerline 16 to 18 in from the side wall.

Next to a vanity, the 15 in is measured from the toilet's centerline to the edge of the vanity, not to the bowl. A toilet between a vanity and a tub needs 30 in between the two at the very least. Planning a full bathroom around a tub? See standard bathtub size.

How to measure a toilet

Measure from the finished wall, not from the baseboard.

1. Rough-in. Measure from the finished wall behind the toilet to the center of one of the bolt caps that hold the toilet to the floor. You will get close to 10, 12 or 14 in.
2. Depth. Measure from the same wall to the front edge of the bowl. A new toilet should be no deeper if your door or vanity is close.
3. Width. Measure across the widest point, usually the tank. Then measure from the toilet's centerline to the nearest wall, vanity or tub on each side.
4. Height. Measure from the floor to the top of the tank lid. If there is a shelf or cabinet above, measure up to its underside too.
5. Rim and seat height. Measure from the floor to the top of the rim with the seat lifted, then to the top of the closed seat.
6. Bowl length. Measure from the midpoint between the seat holes to the front of the rim: about 16½ in is round, about 18½ in is elongated.
7. Clear space in front. Measure from the front of the bowl to the nearest wall, fixture or door. Less than 21 in is below the code minimum.

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