Toilet Seat Sizes: A Complete Guide to Choosing the Right Fit
Dimensions you need to know.
Standard toilet seats come in two main sizes – the round toilet seat is approximately 16.5", while the elongated toilet seat is a bit longer at 18.5". Knowing which toilet seat size your toilet requires and how to measure for it correctly can save you time and money while refreshing your bathroom. Read on for more information on standard toilet seat sizes and tips on selecting the perfect fit for your toilet.
What Are the Standard Toilet Seat Sizes?
There are two main toilet seat sizes, including round and elongated. Both of these standard options have the same width of 14" but vary in length.
Round Toilet Seat
Dimensions: 16.5" – 17.5" long and 14" wide
Best for: Smaller bathrooms and budget bathroom remodels
Elongated Toilet Seat
Dimensions: 18.5" – 19.5" inches long and 14" wide
Best for Enhanced comfort and larger bathrooms
Tip!
Not sure which toilet seat type is best for your bathroom? We’re here to help! Check out our guide for an in-depth comparison: Round vs. Elongated Toilets: Which One Is Right for You?
How to Measure a Toilet Seat
An easy way to ensure you’re choosing the right toilet seat replacement is to measure your current one. Follow these steps to get correct measurements every time.
1. Measure the Length
While the standard toilet seat lengths are fairly consistent for the two types, this may still vary slightly. Get a correct measurement of the length by placing the tip of your measuring tape at the back outer edge of your toilet seat and measuring to the front outer edge of the front of the toilet seat. This is your toilet seat length.
2. Measure the Width
To get the exact width measurement of your toilet seat, measure from the left outer edge of the toilet seat to the right outer edge. This is your width.
3. Measure the Bolt Spacing
Measure the distance between the two bolts that connect the hinges of the toilet seat to the toilet base. This distance is typically 5" – 6", but can vary, so it’s important to get an exact measurement to make sure your new toilet seat is compatible with your toilet.
Non-Standard Toilet Seat Sizes
While most toilets are compatible with one of the two standard toilet seat sizes, there are some exceptions. Depending on the measurements of your toilet, you may want to consider non-standard toilet seat sizes before making your final decision.
- Compact-Elongated: This toilet seat type has the oval shape of an elongated toilet seat, but is approximately the same length or slightly longer than a round toilet seat. This gives you the elongated shape, but still fits into tighter spaces and works with shorter toilets.
- One-Piece Toilets: One-piece toilets are designed with the tank and bowl connected as one single piece. The toilet seat will still be separate, but you may need a specific toilet seat model that is compatible with a one-piece toilet. Measure carefully and check all product specifications to make sure your toilet and seat are compatible.
- Specialty Shapes & Bidet Toilet Seats: Some toilets may require specialty-shaped toilet seats, which will be listed in the product manual. If you go with a bidet toilet seat, which is thicker than your standard toilet seat and has additional components, you will need to pay special attention to the measurements and follow the product specifications and instructions for the specialized toilet seat.
Tip!
There are more than measurements to consider when choosing a toilet and compatible toilet seat. Check out our helpful guides that cover everything you need to know about choosing a toilet:
Toilet Buying Guide
What Is the Standard Toilet Height?
One-Piece vs. Two-Piece Toilets: Which Is Right for You?
Common Mistakes When Choosing a Toilet Seat
The right measurements make choosing a toilet seat easy. Avoid these common mistakes when measuring to save yourself the hassle of having to return an incompatible toilet seat.
- Not measuring accurately: It’s always best to double-check measurements instead of assuming that a round or elongated toilet seat will fit. Models can vary slightly, causing things to look or feel off.
- Assuming all toilets are the same size: Even if your toilet appears to be a standard size, there are some that have non-standard measurements and require a specialty-shaped or size toilet seat. Measuring or consulting the product manual for your toilet is the only way to be sure.
- Ignoring bolt spacing While the toilet seat may be the perfect size for your toilet, if the bolt spacing doesn’t align, you won’t be able to use it. Bolt spacing can vary slightly, but it must be an exact match to allow for proper installation, so measure first for a perfect fit.
- Skipping shape difference: Don’t ignore toilet seat shape when choosing the right one for your toilet. Especially in the case of a compact-elongated toilet, you will want to make sure you choose an elongated seat, even though the measurements will be closer to a round toilet seat.
Tip!
Once you’ve made your selection you’ll need to know how to install your new toilet seat, we’ve got you covered. Check out our guide on How to Replace a Toilet Seat.
Frequently Asked Questions
1. What is the most common toilet seat size?
The most common standard toilet seat size is elongated, measuring about 18.5" long and 14" wide. Round seats (about 16.5" long) are also common, especially in smaller bathrooms.
2. How do I know what size toilet seat I need?
To determine what size toilet seat you need, measure the length, width, and bolt spacing of your current seat. If the length is around 16.5", you need a round seat; if it’s around 18.5", you need an elongated seat.
3. Can you replace a round seat with an elongated one?
No, you can’t replace a round seat with an elongated one. The toilet seat dimensions and shape must match the bowl for a proper fit.
4. How do I measure a toilet seat without removing it?
To measure a toilet seat without removing it, measure from the back outer edge to the front for length, across the widest point for width, and between the mounting bolts for spacing.
