Show what you have
A seat on its own, a closed lid, or the toilet bowl. Attached seats can stay as they are.
A good fit starts here
Round or elongated toilet seat?
Typical US round bowls measure about 16½ inches; elongated bowls about 18½ inches, from the mounting-hole midpoint to the outside front rim.
Shape estimates may be incorrect. Confirm measurements before buying.
Check your toilet seat shape
Installed, standalone, open, or closed.
Use your phone camera
Scan with your phone, then tap Take a photo.
fit.topseat.comContinue your photo check on your phone.
JPEG, PNG, WebP, or HEIC · Up to 12 MB · Or drag a photo here
BEFORE YOU SNAP
A clear view.
A better starting point.
Use a comfortable angle
An ordinary phone photo is enough to start. We’ll look at the visible outline and perspective.
Let the shape show
Include as much of the seat or bowl as is convenient. A product photo works too.
RoundElongated
D-shapedIllustrative outlines. Your seat or bowl may vary.
Explore the possible results
Preview the four outcomes without uploading a photo.
Round vs. elongated toilet seats: size comparison
The main difference is the outline and front-to-back length. A round seat has a shorter, rounded front; an elongated seat is longer and more oval. Match the replacement seat to the bowl beneath it.
| Feature | Round | Elongated |
|---|---|---|
| Outline | Shorter, rounded front | Longer, oval front |
| Bowl length* | About 16½ in (41.9 cm) | About 18½ in (47.0 cm) |
| Seat choice | A round seat with matching dimensions | An elongated seat with matching dimensions |
*Measure from the midpoint between the mounting holes to the front edge of the bowl. These are typical categories, not dimensions measured from a photo. Width, hole spacing and hinge clearance also matter.
How to measure for a toilet seat
- Lift the lid and seat. Locate the two seat-mounting holes at the back of the bowl. Do not use the back edge of the lid as your starting point.
- Measure the bowl length. Run the tape from the midpoint between those holes to the outside front edge of the bowl.
- Check width and hole spacing. Measure the widest part of the bowl and the distance from the center of one mounting hole to the other.
- Compare the product specifications. Check the replacement seat’s dimensions and hinge requirements before ordering.
Can a photo tell me whether my seat is round or elongated?
A photo can provide a starting estimate of the visible seat, lid or bowl outline. Camera angle, a closed lid or an obscured edge can be misleading. A photo cannot establish the bowl’s dimensions. If the estimate and your measurements disagree, recheck the measurement and product specifications.
Will an elongated seat fit a round toilet?
Round and elongated seats are not generally interchangeable. Even if the bolts attach, an elongated seat may overhang a round bowl. A round seat on an elongated bowl can leave the front uncovered. Choose the shape and dimensions that match your bowl.
What if the measurement is between the typical sizes?
Do not round the measurement to force a category. Check the starting point, measure again and look for the toilet’s model information. Compact elongated and other nonstandard bowls may need a specific replacement.
What about D-shaped or square toilet seats?
A flat-backed D-shaped, square or specialty bowl may not match either standard category. Use the toilet model and the manufacturer’s dimensions to find a compatible seat.
Try the photo shape checkerFull toilet seat buying guideShop round toilet seatsShop elongated toilet seats