Measurements can help narrow down a replacement toilet tank lid, but they should not be the only thing you use. Two lids can have nearly identical outside dimensions and still have different curves, underside lips or corner shapes.
How to measure the lid
- Place the lid on a flat surface.
- Measure the maximum length from left to right.
- Measure the maximum front-to-back width.
- Note whether the front edge is straight, bowed or sharply curved.
- Look underneath and note the location and shape of the retaining lip.
Measure to the nearest 1/8 inch when possible
Small differences matter with porcelain tank lids. A lid that is one-half inch too long or has the wrong underside contour can rock, overhang or fail to seat on the tank.
Measurements are a filter, not proof of fit
The best match uses manufacturer + tank number + lid number + shape + measurements. If you have only dimensions, use them to create a shortlist and then compare photos and markings.
What if the old lid is broken?
If you still have the pieces, measure the widest overall dimensions and photograph the underside. If the lid is missing completely, measure the top rim of the tank and find the tank's model number before shopping.
Start with our replacement toilet tank lids. You can also browse by brand or color to narrow the search.