How to replace a toilet seat
Quick answer: Check the shape of your pan (D, oval or square) and how the old seat fixes on (top fix or bottom fix), undo the nuts under the back of the pan, lift the old seat off, fit the new one in the same holes and tighten the fixings evenly.
A cracked, stained or wobbly toilet seat is a quick and cheap thing to put right. The main job is getting the right seat: shape, length and fixing type.
Many seats are universal, but it is worth measuring the pan before you buy.
What you will need
- A new toilet seat that fits your pan
- A screwdriver and an adjustable spanner
- Penetrating oil (if the old fixings are stuck)
- Gloves and a cloth
- A tape measure
- A hacksaw (only if the old bolts are stuck and cannot be undone)
Step by step
Measure up
Measure the distance between the two fixing holes at the back of the pan (centre to centre), the width of the pan and its length from the holes to the front. Note the shape: D-shape, oval or square. Many shops list pan sizes.
Pick a seat
Choose a seat that matches the shape and sizes. A soft-close seat lowers slowly. Check whether it uses top-fix or bottom-fix hinges.
Take off the old seat
Lift the cover over the fixing caps at the back and undo the screws or hinge posts. Under the pan you may find a nut, often plastic and awkward to reach, holding each fixing. Hold the bolt top while you undo the nut.
Deal with stuck fixings
Spray penetrating oil on corroded bolts and leave it for 10 minutes. If a bolt will not budge, carefully cut it with a hacksaw. Protect the china with tape.
Clean the pan
Clean around the holes and under the old seat with disinfectant.
Fit the new seat
Put the new hinge posts through the holes, with the seat in the right position, and tighten the nuts under the pan. Tighten evenly and not too hard, or you can crack the pan.
Test and adjust
Close the seat and check it lines up with the pan. Move the hinge slightly before tightening fully if you need to centre it.
Tips
- A soft-close seat is usually the same fitting as a normal one, with a damper in the hinge.
- Take a photo of the old seat's fixings before you remove it.
- Most seats in the UK use a 'top fix', where the fixing is tightened from above. Check the instructions.
Stop and get help if
- The pan itself is cracked or leaking at the base.
- The fixings are corroded and cannot be removed without risk of damaging the toilet.
- The pan is a wall-hung or back-to-wall unit with unusual fixings. Ask a plumber.
- The pan is an unusual shape and no seat will fit. Look for a made-to-measure one.
Would you rather we did it?
We cover Sandwich and East Kent. Send us a quick message on WhatsApp, ideally with a photo, and we will come back with a price and a day.
Common questions
How do I know what toilet seat fits my toilet?
Measure the distance between the fixing holes, the pan width and length, and note the shape. Many suppliers list size charts. Take the old seat to a shop if possible.
What is a top-fix toilet seat?
A top-fix seat has its fixings tightened from the top, so you do not need to get underneath. It is easier to fit and remove.
Can I fit a soft-close seat to any toilet?
Usually yes, if the shape and hole spacing match. The soft-close part is in the hinge.
More guides
Last reviewed 17 October 2026. This guide is general information for UK homes and is not a substitute for the manufacturer's instructions. If the job involves gas, mains wiring, asbestos, structural work or working at height, or you are unsure, ask a suitably qualified person.