Toilet seats explained: D shape, O shape and more
A toilet seat looks like a simple buy until you get it home and it overhangs the pan, or the hinges don't line up. Seats are made to suit particular pan shapes and sizes, and modern pans in particular often need the exact seat made for them. Here's a plain guide to the shapes, how to measure, and when a new seat is the fix versus a new toilet.
The common shapes
Round (O shape)
The classic shape on many older pans. Fairly round, shorter from front to back.
Elongated or oval
Longer from the hinges to the front, often more comfortable. Common on newer toilets.
D shape (square front)
Straight at the back, squared off at the front. Made for modern square-style pans and usually specific to the model.
Model-specific seats
Many modern suites only take the seat designed for them, with hidden or quick-release hinges.
How to measure for a new seat
- Length: from the centre of the hinge holes to the front edge of the pan.
- Width: across the widest part of the bowl rim.
- Hinge spacing: the distance between the centres of the two hinge holes.
- Shape: trace the rim on paper if you're unsure.
- Brand and model: check under the pan or inside the cistern lid. If you can find them, buy the matching seat.
Features worth having
- Soft close: the lid lowers itself quietly, no more slamming.
- Quick release: the seat lifts off for cleaning around the hinges.
- Bidet seats: electronic seats with wash functions. See bidet seats.
Seat or new toilet?
If the pan is cracked, leaks, or the matching seat is no longer made, a new toilet suite is often the better fix. If the toilet is sound, a correctly matched seat is a quick upgrade. We fit seats, bidet seats and complete toilets, with a fixed price before any work starts. See toilet replacement.
Why locals call us
- Local to Matraville and the southern Eastern Suburbs
- Free on-site quotes, with a fixed price before any work starts
- Lifetime labour warranty on our workmanship
- 100+ five-star Google reviews
- Licensed plumbers and gasfitters (Lic. 398171C)
Common questions
What is a D shape toilet seat?
A seat with a straight back and squared-off front, made for modern square-style pans.
How do I know what toilet seat fits my toilet?
Measure the length, width and hinge spacing, and check the pan's brand and model. The matching seat for that model is the safest choice.
Are toilet seats universal?
Some are close to universal for older round or oval pans, but many modern pans need the specific seat made for them.
Can you fit a toilet seat for me?
Yes. We fit standard, soft-close and bidet seats, and can supply the right one for your pan.
Related help: toilet replacement, bidet seats, back vs bottom inlet toilets and taps and toilets. Local pages: taps and toilets Matraville, taps and toilets Maroubra, taps and toilets Botany and taps and toilets Pagewood. Browse all our plumbing guides.