USPS parcel sizes: check inches, pounds and the selected product
Measure the sealed outer parcel, keep its units consistent and check size, weight and pricing conditions for the actual USPS product before creating a label.
Reviewed 2026-10-08 · 2 min readMeasure the package that will actually be mailed
Use the sealed outer parcel, including any protrusions, rather than the unpacked item or a supplier’s suggested box. Record gross weight with the final protective material and label. Recheck the result after a bundle or carton is changed.
USPS defines length as the longest dimension and girth around the remaining sides. For a rectangular package, length plus girth is the longest dimension plus twice each of the other two dimensions. Keep irregular shapes with their applicable measurement instructions.
Keep the measurement units visible
Store the original measurement and the units used. Convert consistently before entering values into a label or quote. Avoid mixing centimetres with inches or a product’s net weight with the packed parcel’s gross weight.
| Check | Record or next action |
|---|---|
| Length, width and height | Final outer dimensions with their unit. |
| Girth | Applicable method for the actual package shape. |
| Weight | Gross packed weight with its unit. |
| Label input | Values entered for the selected carrier product. |
Check the selected product’s limits and charges
USPS size guidance distinguishes the general domestic limit from the larger Ground Advantage allowance and also describes additional pricing conditions. Confirm the current standard for the purchased product and destination. Being within an outer size limit does not establish that the quoted price has no dimensional or nonstandard charges.
For a hypothetical rectangular parcel measuring 18 by 12 by 10 inches, girth is 44 inches and length plus girth is 62 inches. That calculation describes size; a product eligibility and price check still needs the weight, contents and destination.
Resolve a mismatch before buying or supplying the label
If the final parcel differs from the quote or issued label, ask the responsible account holder to review the correct action. Keep an approved replacement label linked to the earlier record. Do not dispatch using measurements that describe another package.
For outsourced repacking, agree who measures after sealing and who receives adjustment notices. Retain the final measurement record with the order so a later charge can be compared with the package that was mailed.