Toilet rough-in: how to measure before you buy
The rough-in is the distance from the wall behind the toilet to the center of the drain. Buy the wrong one and the toilet will not fit, or will sit oddly far from the wall.
How to measure
Measure from the finished wall, not the baseboard, to the center of the floor bolts that hold the toilet. If there are two sets of bolts, use the back ones. Use the rough-in calculator to check.
Common sizes
- 12 inches: by far the most common.
- 10 inches: often in older homes and tight baths.
- 14 inches: found in some older houses.
If yours is unusual
Many toilet models are made in 10- and 14-inch versions. Offset flanges exist, but choosing the right rough-in is cleaner. During a remodel, the drain can often be moved to a standard spot.
Clearances
Building codes call for at least 15 inches from the center of the toilet to a side wall or fixture and 21 inches of clear space in front. More feels better. See small bathroom layouts.
Choosing the toilet
See the toilet buying guide, comfort height toilets and toilets.
Common questions
What is the standard toilet rough-in?
Twelve inches from the finished wall to the center of the floor bolts is the most common.
Do I measure from the baseboard or the wall?
From the finished wall surface, not the baseboard.
Can I put a 12-inch toilet on a 10-inch rough-in?
No, it will not fit against the wall. Choose a 10-inch rough-in model or have the drain moved.
Shop toilets
Order online, pick up in Keene, or ask us about installation.
Book a consult
Tell us the room, a rough budget range and when you'd like to start. We'll come back with next steps and a realistic timeline, no pressure, no mystery pricing.
