How to Know Your Toilet Seat Size – An Expert‘s Guide

Hey there! As an expert in home renovations and repairs, I know first-hand how tricky it can be to figure out your toilet seat size and find the right replacement. With so many shapes, sizes, and specs to consider, it‘s easy to feel overwhelmed. Well, don‘t stress! In this comprehensive toilet seat size guide, I‘ll walk you through everything you need to know to find the perfect fit.

After 15 years of helping homeowners install new toilets and replace toilet seats, I‘ve learned all the tips and tricks to getting it right. Whether your goal is upgrading to a more comfortable elongated seat or finding a replacement for an old, cracked seat, I‘ve got you covered. I‘m excited to share my knowledge to help you take the guesswork out of getting the right toilet seat size. Let‘s dive in!

Materials You‘ll Need

Before you start measuring your toilet, grab these essential tools:

• Tape measure (flexible "tailor‘s tape" style is ideal for this project)
• Pen and paper for writing down measurements
• Flashlight or headlamp if lighting under the toilet is poor

How to Measure Your Toilet Bowl

Measuring the length and width of your existing toilet bowl is the most important step to finding what size seat will fit properly.

Here‘s a simple step-by-step process:

1. Remove the Old Toilet Seat

The first thing you‘ll want to do is take off the old toilet seat so you can get accurate measurements. Start by turning off the toilet‘s water supply valve before flushing to empty out all water from the tank and bowl.

Once it‘s empty, unscrew the nuts or bolts on the underside of the seat using an adjustable wrench or pliers. These are likely covered by plastic caps that you can pry off with a small flathead screwdriver. Set aside the hardware to reuse later if it‘s still in good shape.

2. Measure Bowl Length

Now that the old seat is removed, you‘ll want to measure across the toilet bowl from the center of each bolt hole. Place your tape measure across what is typically the widest part of the bowl.

• For round bowl toilets, this length is typically 16 to 17 inches.
• For elongated bowl toilets, this length is usually 18 to 19 inches.

Write down this important length measurement to reference later.

3. Measure Bowl Width

The next step is determining the width of the toilet bowl. Measure from left to right at the widest part, which is usually around the middle of the bowl.

• Round toilet bowls generally have a width of about 14 inches.
• Elongated bowls are usually 16 to 17 inches wide.

Note down the toilet bowl width for comparison with potential new seats.

4. Measure Rim Height

Lastly, you‘ll want to check the height of your toilet bowl by measuring from the floor to the top of the rim where the seat mounts.

• Standard height toilets typically have a rim height of around 14 to 15 inches.
• Comfort or right height toilets measure between 17 and 19 inches high.

Make sure to record the rim height measurement. This determines if you need a standard or comfort height toilet seat.

5. Note Bowl Shape

In addition to the length, width, and height, take a second to note whether your toilet bowl has an elongated oval shape or a circular round shape.

With these key toilet bowl measurements in hand, you‘ll know exactly what size seat you need!

Toilet Seat Dimensions

Now that you know how to measure for the right seat, it helps to understand the common toilet seat shapes and sizes.

There are two main factors that determine toilet seat dimensions – the bowl shape and height.

Round vs. Elongated Seats

These refer to the shape of the toilet bowl they fit:

• Round – Round bowls and seats have a circular shape. Round seats measure about 16-17 inches long x 14 inches wide.
• Elongated – Elongated bowls and seats have an oval shape about 2 inches longer. Elongated seats are 18-19 inches long x 16-17 inches wide.

Elongated seats feel more comfortable but do take up more space.

Standard vs. Comfort Height

This describes the total toilet height and rim height off the ground.

• Standard – Standard toilets have a rim height of around 14-15 inches and overall height of about 27-28 inches.
• Comfort/Right/ADA Height – These toilets have increased rim height of 17-19 inches and total toilet height of about 30-31 inches.

Comfort height seats are easier to sit on and stand up from for most adults. The ADA requires minimum 17-inch height for accessibility.

Here is a comparison of the common toilet seat sizes:

Shape	Bowl Dimensions	Seat Dimensions	Height
Round	16-17" long x 14" wide	16-17“ long x 14” wide	Standard: 14-15” rim height
Elongated	18-19” long x 16-17” wide	18-19” long x 16-17” wide	Comfort: 17-19” rim height

This gives you an easy reference to compare your toilet measurements against standard seat sizing.

Other Toilet Seat Factors

In addition to the core size, height, and shape, there are a few other factors that can impact your toilet seat selection:

Style and Design

• Color – White, black, beige, grey, blue, wood tone, and more colors are available to match your bathroom aesthetic.
• Material – Molded plastic or wood seats offer different looks. Wood is warmer but requires more maintenance. Plastic is affordable and easy to clean.
• Open vs closed front – Open front seats have a u-shape opening and are easy to keep clean. Closed front seats offer full coverage.
• Specialty shape – Some seats have unique shapes like square, keyhole, triangle cutouts, or extra elongated.

Features and Add-Ons

• Soft close – These seats have hinges that close slowly and quietly without slamming.
• Quick-release – Easy removal for cleaning. Pull a lever or press a button to detach from the toilet bowl.
• Nightlight – LED nightlights on the seat provide illumination without turning on harsh overhead light.
• Heated seat – Heated toilet seats keep the surface cozy. Look for adjustable temperature settings.
• Antimicrobial – Antimicrobial coating helps inhibit bacteria, mold, and odors.

Measuring Toilet Seat Bolt Holes

In addition to toilet bowl size, you‘ll need to measure the toilet seat mounting bolt holes to ensure the new seat will align properly.

Here are some tips for accurately measuring bolt holes:

• Use an adjustable wrench to fully loosen and remove the nuts from the bolt holes. Take them out and set aside.
• Measure center-to-center between the two bolt holes. Standard spacing is 5-7 cm or 2-2.75 inches.
• Check the diameter of each bolt hole. Standard size is around 12mm or 0.47 inches.
• Note that sometimes one hole may be a keyhole slot. Be sure to measure the round part of the keyhole.
• Compare your bolt hole spacing and diameter to the specs of any new seat. They must match up!

Getting the proper bolt hole sizing ensures secure and correct installation of the new toilet seat.

Finding Compatible Toilet Seat Bolts

Along with the right sized seat, you‘ll need bolts that properly fit into the mounting holes and holes in the new seat itself.

Here are some tips for finding compatible replacement toilet seat bolts:

• Bring one of your old bolts with you when shopping to match the thread size and diameter. Standard is 1⁄4 inch – 20 thread size, around 2.5 inches long.
• Look for bolts with ceramic coating to prevent corrosion and add durability.
• Choose bolts with plastic or metal capped covers for a streamlined look.
• Ensure the bolt head shape and size fits into holes on the new toilet seat.
• Pick up rubber or plastic washers to prevent loosening over time.

Reusing old bolts is fine if they’re in good shape. Just make sure your new seat and old bolts align!

Adjusting a Toilet Seat for Proper Fit

If your new toilet seat sits a little uneven or doesn‘t align completely flush with the bowl, have no fear! There are some easy ways to tweak and adjust the seat for an optimal fit:

• Use the adjustable side bolts to raise or lower each side until level.
• Place plastic shims under the seat mount at contact points to change the angle.
• Carefully file or sand the underside front of the seat to tilt it forward or back slightly.
• Add foam weatherstrip pads or tape to fill small gaps between seat and bowl.
• Adjust the lid support post or chain length so the tank lid aligns smoothly.

Taking a few minutes to fine tune your toilet seat installation ensures maximum comfort, proper sealing, and minimal rocking or looseness.

Identifying 10 vs 12 Inch Toilet Rough-In

If you need to replace the entire toilet, it‘s crucial to identify whether you have a 10 or 12 inch rough-in.

Here‘s how to determine and measure the rough-in size:

• Remove toilet to access bolts and piping underneath. Turn off water supply first and empty bowl.
• Measure from the wall straight out to the center of the waste pipe outlet.
• 10” rough-in will measure about 10” from wall to midpoint of outlet pipe.
• 12” rough-in will measure about 12” from wall to outlet pipe center.

Matching rough-in size is necessary for the toilet to align with the waste pipe correctly.

Finding Toilet Seats for Round vs. Elongated Bowls

Searching for the right seat based on your oval elongated or round bowl shape is made easy with these tips:

For round bowls:

• Measure diameter across widest section of round bowl. Round bowls are typically 14 inches wide.
• Choose a round seat between 16-17” long x 14” wide.

For elongated bowls:

• Measure the longest front-to-back part of the oval bowl. Usually 18-19 inches.
• Look for an elongated seat about 18-19” long x 16.5-17.5” wide.
• Elongated seats often have decorative chrome hinges.

Matching the same shape toilet seat to your existing bowl ensures proper fit and function.

Buying Toilet Seats Online

Thanks to the convenience of online shopping, finding and purchasing a new toilet seat from the comfort of home is now super simple. Just follow these tips:

• Browse major retailers‘ websites and filter specifically for toilet seats to see options.
• Use detailed product specs, dimensions, images, and customer reviews to compare.
• Match your toilet measurements to listed seat dimensions to find the right size, shape and height.
• Check sizing charts against your toilet size if dimensions aren‘t listed.
• Select the ideal seat material, features, and design for your needs.
• Add to cart, enter payment and shipping info, and your new seat ships to your door!

Buying toilet seats online provides wider selection and easier size matching than in-store. With accurate toilet measurements, you can successfully shop online for the perfect replacement toilet seat fit.

Frequently Asked Questions About Toilet Seat Sizes

Here are answers to some of the most common toilet seat size questions I get asked:

What are the different toilet seat sizes?

The main toilet seat sizes are round and elongated. Round seats are about 16-17” long by 14” wide. Elongated seats measure 18-19” long by 16-17” wide.

What’s the most common toilet seat size?

The standard round size of about 16-17” long x 14” wide is the most popular for its versatility to fit most toilets. Elongated is also widely used for the added comfort.

How do I know if I have a round or elongated toilet?

Round bowls are circular in shape and measure about 16-17” across. Elongated bowls are oval and around 18-19” at the longest point. Measure yours to check!

What size is a standard height toilet seat?

Standard height toilet seats are sized 16-17” long x 14” wide for round bowls and 18-19” long x 16-17” wide for elongated bowls. They fit 14-15” rim height toilets.

What toilet seat size is ADA compliant?

ADA guidelines require a minimum 17” toilet seat height measured from floor to seat top. Comfort height seats in both round and elongated sizes meet ADA requirements.

My toilet seat is loose – how do I fix this?

Check that bolts are tight enough. Add a second nut on each bolt threaded together to lock it. Replace worn out nuts/bolts. Use brass bolts instead of plastic. Apply thread locking fluid.

The Right Toilet Seat = Comfort + Function

I hope this toilet seat sizing and measuring guide gives you the confidence to find the perfect model for your bathroom. Taking detailed toilet bowl measurements and understanding standard seat sizes is the key to success.

With the right tools and know-how, you can remove your old seat, quantify exactly what size replacement you need, and install the new seat securely.

If you have any other toilet or bathroom renovation questions, don’t hesitate to reach out! I’m always happy to share my years of home improvement experience. Finding and installing the ideal toilet seat is extremely rewarding when you get that “just right” fit.