How to Measure a Package for Shipping
Carriers re-measure packages at their facilities and bill charge corrections when your stated dimensions are under. Measuring the way they do removes the surprise.
Measure the extremes, including bulges
Measure each side at its widest point — including bulges, taped corners, and handles. A box that is 47.9 in on the label is 48 in to the carrier the moment one corner bulges. For soft packages, measure the package as it sits on a scale: settled, not squeezed.
Know the rounding rule
- FedEx, UPS, and USPS: every fraction rounds UP to the next whole inch. 47.1 in is 48 in.
- DHL Express: no published convention — DimCheck rounds to the nearest whole centimeter as a working assumption.
That means the safe way to measure is: measure to the fraction, then round the way the carrier will. The calculator applies each carrier's rounding for you.
Which side is the length?
The longest side. Carriers compute girth from the two shorter sides and length + girth as longest + 2 × second-longest + 2 × shortest. DimCheck sorts your sides automatically — use the length + girth calculator if you want to see the numbers.
Weigh on a calibrated scale
Weigh the fully packed, labeled package. FedEx and UPS round actual weight up to the next whole pound; USPS Priority Mail does the same. A 8.1 lb package bills at 9 lb.