Geberit has put together a guide to installing wall hung toilets at the optimal height for your home. Owners usually will have a preference for the seat height on their wall-hung toilet bowl. This can be to accommodate taller or shorter users – or sometimes to meet ADA guidelines. Depending on the bowl used, Geberit carriers can accommodate 15-19”+ seat heights. Different bowls have different dimensions from bolts to rim heights. Rim is (typically) 3”-4” above bolt height – you’ll need to know this info before setting the carrier height. Carrier height is (typically) set before the finished floor thickness is set. Basing the carrier height on rough floor height will result in errors.

Info needed to (correctly) set the bowl height:
1) Client preferred seat height (target height)
2) Dimension from bolt holes to rim height (from bowl spec sheet)
3) Thickness of finished floor above sub floor
4) Thickness of seat

Here’s the formula:
[Target Height] – [Seat Thickness] – [Distance From Rim/Bolts] + [Finished Floor Height] = Carrier Height

Example: TOTO Aquia is 3 1/2” rim height above bolt holes. The finished floor is 3/4” marble on top of 1/2” mortar, on top of plywood sub floor. The Washlet seat is 1” thick above the Aquia rim height. The consumer wants the top of the seat to be 17” above the finished floor.

How high does the plumber set the Geberit bolts? Plugging the numbers into the formula, the math is simple:
[17] – [1] – [3 1/2] + [1 1/4] = 13 3/4