Mansfield toilet tank lids can be confusing because the number on the toilet tank and the part number on the replacement cover are not always the same. The safest way to find a replacement is to identify the tank first, then use the lid number, measurements and underside shape to confirm the fit.
Start with the Mansfield tank model number
Carefully remove the lid and inspect the inside walls of the tank. Record every stamped, printed or molded number you can find. If you still have the original lid, inspect its underside as well.
Do not assume the tank number is also the lid number. Mansfield parts literature shows why this matters. For example, the 160-LID tank cover is documented for a group of Mansfield tanks that includes models 160, 161, 170, 172, 173, 174, 180 and others. In other words, several tank numbers can legitimately point to one replacement lid part number.
Use the number as the primary clue
Searching only for “Mansfield white toilet lid” is too broad. A better search combines the brand with every number you found. Try the tank number, the lid number if present, and versions with or without a hyphen.
FixALid organizes replacement listings around these searchable model and part-number relationships. Our current catalog includes the Mansfield 51 tank lid, listed for the Mansfield 35 family.
Measurements confirm a match; they do not create one
Measure the lid at its widest side-to-side point and its maximum front-to-back depth. If the lid is missing, measure the top of the tank and photograph the rim. Measurements are useful for eliminating obvious mismatches, but two lids with similar dimensions can have different corner radii, rear contours or underside locating tabs.
Compare the underside
The underside is often more useful than the glossy top surface. Look at the inner lip, feet, ribs, corner geometry and any molded markings. A lid that is close in overall size can still rock, overhang or fail to seat if the underside profile is wrong.
Older Mansfield lids may require a discontinued-part search
Mansfield continues to document service parts for many toilet families, but older colors and discontinued configurations may no longer be available as new factory parts. In those cases, a used original porcelain lid can be the best way to preserve the existing toilet.
Mansfield identification checklist
- Find the Mansfield tank model number.
- Inspect the original lid for a separate part number.
- Measure width and front-to-back depth.
- Photograph the top, underside and tank markings.
- Confirm the exact shape before choosing color.
Browse current Mansfield toilet tank lids, or use our complete toilet tank lid identification guide. You may also want the guides on finding the toilet model number, measuring a replacement lid, and finding discontinued lids.