Take the old seat off first
Every measurement taken with the old seat in place is a measurement of the seat you already have. It overhangs the ceramic, and that overhang is exactly the error.
The three measurements
Hinge hole spacing — centre to centre between the two holes in the pan. Close to universal at around 155 mm on European ceramics, and worth confirming rather than assuming.
Length — from the centre line of the hinge holes to the outside front edge of the pan. Roughly 40 to 48 cm across ordinary pans, and the measurement that makes a seat look right or wrong.
Width — at the widest point of the bowl, which settles the shape: oval, D-shape or square.
The two fixings
Bottom-fix: a bolt down through the hole, a washer, a wing nut underneath. It needs a hand under the pan, which is why a shrouded or wall-hung pan rules it out.
Top-fix: the fitting expands or clamps from above, so nothing is reached from below. Makers state which a seat uses, and on a shrouded pan it is not a preference.
The part that decides how long it takes
The old bolts. In that damp recess, plated steel corrodes and seizes; stainless steel does not. A seized bolt means cutting it, which turns ten minutes into an hour and is the argument for buying a seat whose fittings are stated as stainless.
Two features worth the money
Quick-release, which lets the seat lift off its hinges for cleaning underneath. It is the feature people miss most once they have had it.
A hinge sold separately. Soft-close is a damper and a damper is a wear part. A seat whose hinge can be replaced is a seat that lasts twice as long as one whose cannot.
Questions people actually ask
Why does my seat slide sideways?
Either the fixing has loosened — retighten it, that is normal maintenance — or the seat is the wrong length for the pan and pivots on its hinges every time it is used. The second is not fixable by tightening.
Can I fit a soft-close seat to any pan?
To any pan whose three measurements match. Soft-close is a property of the hinge, not of the ceramic, and the hinge fits wherever an ordinary one does.
Last reviewed 5 September 2026
