How to Replace a Toilet Seat

Replacing a toilet seat is one of the simplest home repairs you can do. Whether your current seat is cracked, stained, wobbly, or you just want an upgrade, this is a job that requires no plumbing knowledge, no special tools, and about 10 to 15 minutes of your time. If you live in Los Angeles and your toilet seat has seen better days, this guide will walk you through every step from measuring to installation.

A toilet seat replacement is also one of the most common requests we get at GoldKey Repairs. While it is absolutely a DIY-friendly project, some homeowners prefer to have a handyman handle it — especially when dealing with rusted bolts on older toilets or when upgrading to a bidet seat that needs a water connection. Either way, this guide has you covered.

Step 1: Measure Your Toilet Bowl

Before you buy a new toilet seat, you need to know which size to get. Toilet bowls come in two standard shapes:

• Round — Measures approximately 16.5 inches from the mounting bolt holes to the front edge of the bowl. The bowl looks circular from above. Round toilets are common in older Los Angeles homes built before the 1980s and in smaller bathrooms where space is tight.
• Elongated — Measures approximately 18.5 inches from the mounting bolt holes to the front edge. The bowl has an oval shape. Most newer homes and renovated bathrooms in LA have elongated toilets.

To measure, place the end of a tape measure at the center point between the two mounting bolt holes at the back of the bowl. Measure straight to the very front edge of the bowl. If you get a number close to 16.5 inches, buy a round seat. If it is closer to 18.5 inches, buy an elongated seat. Getting the wrong size is the most common mistake people make when they change a toilet seat.

Step 2: Remove the Old Toilet Seat

The old seat is held in place by two bolts at the back of the bowl. Here is how to remove it:

1. Locate the two mounting bolts. They are usually covered by small plastic caps. Pry the caps open with a flathead screwdriver or your fingernail.
2. Use a screwdriver or a wrench to turn the bolts counterclockwise. On most toilet seats, there is a nut on the underside of the bowl that you will need to hold in place while you turn the bolt from the top.
3. Once the bolts are fully loosened, lift the old seat straight up and off the bowl.
4. Clean the area around the bolt holes with a disinfecting wipe or bathroom cleaner. Grime builds up under the seat hinges over time, so take a moment to wipe it down before installing the new seat.

What to Do When Bolts Are Rusted or Stuck

This is where many DIY toilet seat replacements go sideways. In older Los Angeles homes, especially those in coastal neighborhoods like Santa Monica, Venice, or the South Bay, the mounting bolts can corrode from moisture and humidity. If the bolts will not budge, try these approaches:

• Penetrating oil — Spray WD-40 or PB Blaster on the bolts and let it soak for 10 to 15 minutes. Then try again.
• Pliers and screwdriver combo — Grip the nut underneath the bowl with pliers while turning the bolt from above with a screwdriver. This gives you more leverage than fingers alone.
• Hacksaw — If the bolts are completely frozen, you can cut through them with a mini hacksaw. Slide the blade between the bottom of the bowl and the nut, and saw through the bolt. Be careful not to scratch the porcelain.
• Oscillating tool — If you have a multi-tool with a cutting blade, this is the fastest way to cut through corroded bolts without risking damage to the toilet.

If the bolts are plastic (common on seats made after 2010), they will not rust. You can usually just unscrew them by hand or snip them off with a pair of pliers if needed.

Step 3: Install the New Toilet Seat

Installing a new toilet seat is the reverse of removal and takes about five minutes:

1. Unpack the new seat and check that it came with mounting bolts and nuts. Most new toilet seats include hardware.
2. Position the new seat on the bowl so the bolt holes in the hinges line up with the holes in the porcelain.
3. Insert the bolts through the hinges and down through the holes in the bowl.
4. Thread the nuts onto the bolts from underneath the bowl. Hand-tighten first.
5. Use a screwdriver to snug the bolts down. Tighten evenly — alternate between the left and right bolt so the seat stays centered. Do not overtighten. Porcelain can crack if you apply too much force.
6. Close the seat and lid. Check that everything sits flat and does not shift side to side. If the seat slides, tighten the bolts another quarter turn.

That is it. You have a brand new toilet seat installed. The whole toilet seat replacement process, from start to finish, should take about 10 to 15 minutes.

Choosing the Right Toilet Seat

Once you know your bowl shape, you still have a few choices to make:

• Material — Plastic seats are lightweight and affordable ($15 to $30). Wood seats are heavier and feel warmer but cost more ($30 to $60). Duroplast seats offer a premium feel with better resistance to scratches and stains ($25 to $50).
• Soft-close hinges — These prevent the seat from slamming shut. They cost a few dollars more but are worth it, especially in households with children. Highly recommended.
• Quick-release — Some seats have a button that lets you detach the seat from the hinges for easy cleaning. Great for keeping things hygienic.
• Bidet seats — A growing trend in Los Angeles, bidet toilet seats range from $30 for a non-electric model to $300 or more for a heated electric version with warm water, air drying, and a night light.

DIY vs. Professional Cost Comparison

For a straightforward install, this is one of the most cost-effective DIY projects you can do. But if you are dealing with corroded hardware, want a bidet seat with electrical work, or prefer to bundle this with other toilet and faucet repairs, hiring a handyman makes the job hassle-free.

When to Call a Handyman in Los Angeles

While replacing a toilet seat is easy in most cases, there are situations where calling a professional saves you time and frustration:

• Rusted or seized bolts — If penetrating oil and pliers do not work, cutting through corroded bolts without damaging the porcelain requires the right tools and a steady hand.
• Cracked toilet bowl — If you notice a crack in the porcelain around the bolt holes, the entire toilet may need replacement. Do not try to force a new seat onto a cracked bowl.
• Bidet seat with no outlet — Electric bidet seats need a GFCI outlet within reach. If your bathroom does not have one, an electrician or handyman needs to install it safely.
• Bundled repairs — If you also have a running toilet, a leaky supply valve, or other common plumbing problems, it makes sense to have everything handled in one visit.

At GoldKey Repairs, we handle toilet seat replacements and all types of plumbing work across Los Angeles. Our pricing is simple: $150 for the first hour and $85 for each additional hour, plus the cost of parts. A toilet seat swap usually takes well under an hour, so you can bundle it with other small repairs to get the most value from your service call. Check out our full toilet installation cost breakdown for more details.