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Toilet rough-in & clearance checker
One tape measurement tells you which toilet fits your drain, and whether an elongated bowl fits the room.
How to measure rough-in
Measure from the finished wall behind the toilet (not the baseboard) to the center of the floor bolts that hold the toilet down. 12" is standard in most homes; older houses sometimes have 10" or 14". If there are two bolts per side, measure to the back ones.
Round or elongated?
An elongated bowl is about 2" longer than a round one and more comfortable for most adults. Codes want at least 21" of clear space in front of the bowl (24" is more comfortable) and 15" from the center of the toilet to a wall or fixture at the side.
Swapping a toilet
Buying the same rough-in as your drain is what makes a toilet swap a quick job. In New Hampshire our Keene crew does quick toilet swaps on toilets you buy from us.
Common questions
Can I put a 12 inch rough-in toilet on a 14 inch drain?
It will work, but leaves a 2" gap behind the tank. A 14" rough-in model or an offset flange is the cleaner fix.
What is the minimum space in front of a toilet?
Most codes require 21" of clear floor in front of the bowl and 15" from the toilet centerline to any side wall or fixture.
Related tools & pages
Helpful guides & tools
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