How To Fit A New Toilet Seat
Swapping a worn or wobbly seat takes a screwdriver and a little patience with the fixings.
The short answer
To fit a toilet seat, measure the pan so the new seat matches, then undo the old seat's nuts or screws from above or below the pan and lift it off. Clean the area, fit the new fixings through the holes, tighten them most of the way, then clip or screw the seat on, line it up with the pan and finish tightening without overdoing it.
A new toilet seat makes an old bathroom look fresher straight away, and it's one of the quickest jobs on the list. We swap seats regularly across the properties we maintain, whether it's a hinge that's rusted through or a seat that won't stop shifting sideways.
Soft close, wooden and basic plastic seats all go on in much the same way. What changes is the fixing, which tightens from above or below the pan with either a screw or a nut.
How To Measure A Toilet Seat
The easiest option is to buy the same seat as the one you're replacing. If you want a different style, measure the pan first so the new seat lines up with the edges instead of overhanging or sitting short.
These are the measurements that matter:
- Length: From the centre of the fixing holes to the front edge of the pan
- Width: Across the widest part of the pan
- Clearance: From the fixing holes back to the cistern or wall, so the lid can stay upright
- Hole spacing: The distance between the two fixing holes, although most seats have adjustable hinges that suit standard spacing
With those numbers written down, you can compare seats properly. Our roundup of the best toilet seats covers soft close, quick release and wooden designs, and the product listings give the dimensions to check against.
Kit For Swapping A Toilet Seat
- The new toilet seat and its supplied fixings
- A screwdriver or spanner, depending on the fixings
- Bathroom cleaning spray and a cloth
- Rubber gloves
How To Fit A Toilet Seat
1. Remove The Old Toilet Seat
Look at how the old seat is held on before you reach for any tools. Top fixing seats have caps or covers on the hinges that flip or pop off to reveal a screw. Bottom fixing seats have a nut on a bolt underneath the pan, behind the bowl, which you undo by reaching round from below.
Once the screws or nuts are loose, the seat lifts away. The seat in the photo below had rusted where the metal hinges met the fixings, which is exactly why it was coming off.
2. Clean Around The Fixing Holes
With the seat off, you can finally reach the part of the pan that's hidden under the hinges. Spray it with a bathroom cleaner and wipe away the grime and any rust marks before the new seat goes on.
3. Assemble And Test The New Fixings
Unpack the fixings that came with the new seat and put them together following the instructions. Drop them into the holes to test the fit before tightening anything. The pair of photos below shows the new fixing sitting in the hole with its bolt through the pan, and the plate seen from above with its screw and quick release post.
4. Tighten The Fixings Into The Toilet
Once you're happy the fixings suit your pan, fit them properly and tighten the nut or screw so the bases can't move. This seat used rubber cone nuts that wedge up into the hole from below, as the next photo shows.
Fit every washer that comes in the pack, and in the order the instructions show. Some seats come with several, and they're what stops the fixing working loose. Leave the fixings slightly short of fully tight at this stage, as you'll need a bit of movement to line the seat up in the next step.
5. Fit And Align The Toilet Seat
Fit the seat onto the fixings. Quick release seats like the one we fitted simply clip onto the posts you can see below, while others screw on through the hinge.
Close the seat and lid and hold the seat with a hand on each side. Line it up so its shape follows the edge of the pan, then tighten the fixings fully. Stop when the seat is firm, as overtightening can strip a thread or crack the bolt.
6. Test The Seat
Check everything works before you tidy up:
- Soft close: On a soft close seat, the lid lowers slowly on its own
- Quick release: The seat unclips and clips back on easily
- Lift: The seat and lid stay upright when raised
- Fixings: The seat doesn't move or slide when you sit on it
If all four checks pass, the seat is fitted properly and ready to use.
How To Tighten A Loose Toilet Seat
A seat that starts sliding sideways or rocking after a while just needs its fixings nipped up again. You'll need a screwdriver, a spanner or the plastic tool that came with the seat.
Bottom fixing seats are tightened from below. Reach under the back of the pan and turn the nut or cone clockwise, as in the photo below, where we're using the supplied key on a cone nut.
Top fixing seats are tightened from above. Unclip or lift the seat off its fixings, take off any cover and turn the screw to pull the fixing tight. Keep the seat lined up with the pan as you go, and stop as soon as it's firm.
If the seat still slides after tightening, adding an extra washer on the bolt between the nut and the underside of the pan gives the fixing more to grip against. That trick has worked for us on certain seats that refused to stay put.
Making A Toilet Seat Swap Last
Seats with metal hinges rust in a damp bathroom, as our old one showed, so stainless steel or plastic hinges are worth considering for a replacement. A small electric screwdriver speeds up the top fixings when you're changing seats in more than one bathroom, but finish by hand so you don't overtighten.
While the seat's off, it's a good time to look at the rest of the toilet. Mouldy sealant around the base of the pan comes out easily with our guide to removing old bathroom sealant, and a fresh bead from our pick of the best bathroom sealants finishes the job. The tiles behind the toilet are another spot that's hard to reach normally, and cleaning bathroom tiles and grout covers that.
Your Questions Answered
Are all toilet seats a universal fit?
Most toilet seats are sold as a universal fit, which means the hinges adjust to suit the standard spacing between fixing holes. The shape and size of the pan still varies, so a universal seat can overhang or sit short on some toilets. Measure the length, width and clearance to the cistern before buying to get a seat that lines up with the pan.
How do you know if a toilet seat is top or bottom fixing?
Look at the hinges and underneath the back of the pan. A top fixing seat has covers or caps on the hinges hiding the screws, and there's no reachable nut below. A bottom fixing seat has nuts on bolts under the pan. Toilets with closed backs or wall hung pans need a top fixing seat, as you can't get underneath.
Why does my toilet seat keep moving sideways?
A toilet seat moves sideways when its fixings have worked loose or weren't tightened enough to grip the pan. Tighten the nuts or screws while holding the seat in line with the pan. If it keeps sliding, fit an extra washer between the nut and the pan, or switch to a seat with top hat or cone fixings that wedge into the holes.
Is it easier to buy the same toilet seat as the old one?
Yes. A like-for-like seat already matches the pan, so there's nothing to measure. For a different style, take the length, width and clearance back to the cistern first, or the new seat can overhang the edges or stop short of them.
Why not tighten the toilet seat fixings fully straight away?
You need a little play to line the seat up. Once it's on, close the seat and lid, hold it with a hand either side so it follows the shape of the pan, and then do the fixings up firmly. Going past firm risks stripping the thread or cracking the bolt.
What should I check once the new toilet seat is fitted?
Let a soft close lid go and it should settle by itself. A quick release seat should come off and clip back on without a fight. Lift the seat and lid to check they stay up, then sit on it and make sure nothing shifts. Pass all four and the job's done.
Which hinge material lasts best in a damp bathroom?
Stainless steel or plastic. Ordinary metal hinges rust in a damp bathroom, and the old seat we took off had rusted right where its hinges met the fixings. Rust stains the pan around the holes too, so give that area a clean while the seat's off.
Richard has spent years renovating properties and turning them into rentals and Airbnbs. Like a lot of people he started out as a beginner, and these days there isn't much DIY he won't take on.