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Installing a toilet seat takes about ten minutes. Measure the bowl first, buy round or elongated to match, unclip the old hinge covers, undo the two bolts underneath, drop the new seat in and tighten by hand until it stops moving. The only part that goes wrong is the bolts, which are often corroded. Our toilet installation and repair team handles the ones that fight back.
Key Takeaways
- Measure before you buy. Round bowls are about 16.5 inches, elongated about 18.5 inches.
- Bolt spacing is standard at roughly 5.5 inches centre to centre on almost every US toilet.
- Hand tight, then a quarter turn. Over-tightening cracks the porcelain.
- Corroded bolts are the usual problem, and a hacksaw blade solves most of them.
- A seat that will not stay tight usually means worn bushings, not a worn seat.
Measure the Bowl Before You Buy Anything
Nearly every returned toilet seat is the wrong shape. Take two measurements before you go to the store and you will not join that queue.
- Bowl length. From the centre of the two bolt holes at the back, straight forward to the front outside edge of the bowl. About 16.5 inches means round. About 18.5 inches means elongated.
- Bolt spread. Centre to centre across the two holes. Standard is around 5.5 inches. Anything else means a specialty or imported fixture.
- Bowl width at the widest point, useful if you want the seat to sit flush rather than overhang.
Write both numbers on your phone. A seat that is close but not right will rock, and no amount of tightening fixes a shape mismatch.
What You Need
- The new seat, with its bolts and bushings
- An adjustable wrench or a basin wrench
- A flathead screwdriver to lift the hinge covers
- Penetrating oil for corroded bolts
- A hacksaw blade or an oscillating tool, if it comes to that
- Gloves, an old towel and a bowl cleaner
How to Install a Toilet Seat, Step by Step
- Open the hinge covers. The two plastic caps at the back of the seat flip up or slide back. A flathead screwdriver lifts them.
- Hold the nut underneath. Reach under the bowl rim and grip the nut with your fingers or a wrench.
- Turn the bolt anticlockwise from above. Most modern bolts are plastic and turn by hand or with a screwdriver.
- Lift the old seat off and clean the porcelain properly. This is the only time it will ever be this accessible.
- Drop the new bolts through the holes. Fit any rubber or plastic bushings the way the instructions show, because they are what stops the seat sliding.
- Position the seat and check it sits square and central before tightening anything.
- Tighten alternately. A few turns on one side, then the other, keeping it even. Hand tight, then no more than a quarter turn.
- Test it. Sit down, shift your weight side to side. If it moves, nip it up slightly. Then close the hinge covers.
That quarter-turn limit matters. Porcelain does not flex, and a cracked bowl turns a $30 seat into a new toilet.
When the Old Bolts Will Not Budge
Older High Point and Winston-Salem homes often have metal bolts that have been in place for decades. Hard water and time fuse them.
| Problem | What to Try | If That Fails |
|---|---|---|
| Nut spins with the bolt | Grip the nut, turn the bolt | Cut the bolt shaft |
| Bolt head is rounded off | Penetrating oil, wait 15 minutes | Cut with a hacksaw blade |
| Nut is rusted solid | Penetrating oil and a firm wrench | Cut the bolt from below |
| Plastic bolt is stripped | Grip with pliers and twist | Snap it and clear the hole |
To cut a bolt, slide a hacksaw blade between the seat hinge and the porcelain, protect the bowl with a strip of cardboard, and saw through the bolt shaft. Take it slowly. The cardboard is not optional.
Choosing a Seat That Lasts
Beyond the shape, three choices matter in daily use.
- Material. Moulded wood feels solid and warmer. Plastic is lighter, cheaper and easier to keep clean in a family bathroom.
- Soft close. A damped hinge stops the lid slamming. It is the single upgrade most people notice.
- Quick release. The seat unclips from the hinges for cleaning, which matters more than it sounds in a busy house.
Skip the very cheapest plastic seats. The hinges are the failure point and they usually give out within a year or two of daily use.
Toilet Seat Questions We Get Asked
How do I know if I need a round or elongated seat?
Measure from the centre of the bolt holes to the front outside edge of the bowl. Roughly 16.5 inches is round. Roughly 18.5 inches is elongated. Shape matters more than brand, and the two are not interchangeable.
Why does my toilet seat keep coming loose?
Usually the rubber or plastic bushings under the hinges have worn or gone missing, so the seat has nothing to grip. Replacement bushing kits are inexpensive. Tightening harder without them just risks the porcelain.
Can I replace a toilet seat myself?
Yes. It is one of the few plumbing jobs with no water involved and no permit needed. The only part that goes wrong is a seized bolt, and a hacksaw blade handles most of those.
Do all toilet seats fit all toilets?
No. Shape has to match the bowl, and while a 5.5 inch bolt spread covers almost every US toilet, some older, imported or wall-hung fixtures use different spacing. Measure both before buying.
How tight should toilet seat bolts be?
Hand tight plus about a quarter turn. The seat should not shift when you press it side to side. Anything beyond that risks cracking the porcelain around the bolt holes, which cannot be repaired.
When a Wobbly Seat Is Really a Wobbly Toilet
Here is the thing worth knowing. If the whole toilet rocks on the floor rather than just the seat, stop tightening the seat. A rocking bowl means the closet bolts at the floor have loosened or the wax ring seal underneath has failed.
That one leaks into the subfloor every flush, quietly, until the floor gives. It is a far bigger problem than a loose seat and it needs sorting properly.
Call All Star Plumbing at (336) 462-1080 if the bowl moves, if you see water at the base, or if a bolt has seized and you would rather not take a saw to your toilet. A real person answers 24 hours a day, you get upfront pricing before work starts, and if we cannot fix it you do not pay. You can also book a toilet repair online.
Planning an accessible bathroom instead? Read our guide to installing an ADA toilet. For a full bathroom upgrade, our remodel plumbing team covers the whole Triad. If you are replacing the toilet rather than the seat, the EPA’s guidance on water efficient toilets is worth a read first.
Family owned in High Point since 2007, licensed, bonded and insured.
All Star Plumbing
4003 North Main Street
High Point, NC 27265
Phone: (336) 462-1080
Hours: Open 24 hours, 7 days a week
NC Plumbing License #15130
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