Length + Girth Calculator
Length + girth = longest side + 2 × second-longest side + 2 × shortest side. Carriers use it to decide whether a package is oversize, needs additional handling, or can ship at all.
What this means
Girth is the distance around the thickest part of the package: 2 × width + 2 × height, using the two shortest sides. The longest side is the "length". DimCheck sorts your sides automatically — you never need to guess which one is the length.
Relevant rules
FedEx and UPS set a 165 in length + girth maximum and 108 in maximum length; FedEx charges Additional Handling above 105 in length + girth. USPS Priority Mail allows 108 in; Ground Advantage and Parcel Select allow 130 in. DHL Express works in centimeters with piece limits of 120 × 80 × 80 cm and a 300 cm absolute maximum — see carrier rules for the full, sourced list.
Potential action
Near a limit? A one-inch trim on the longest side reduces length + girth by one inch — and one inch can be the difference between an oversize surcharge and a standard package. Check surcharge thresholds on the surcharge checker.
How to use length + girth — step by step
- Measure each side at its widest point, including bulges — the carrier's tape does.
- Identify the longest side — that is the length. The other two are used for girth.
- Compute girth: 2 × second-longest + 2 × shortest.
- Add the length for the length + girth figure this tool shows.
- Compare with the limits that bind you: 105 in (FedEx Additional Handling trigger), 130 in (USPS Ground Advantage/Parcel Select maximum and FedEx Oversize trigger), 165 in (FedEx and UPS absolute maximum). FedEx, UPS, and USPS round each side up to a whole inch first — the calculator applies that rounding before summing, so the number you see is the number the carrier will compute.
Frequently asked questions
Which side counts as the length?
The longest side. Girth is measured around the other two: 2 × second-longest + 2 × shortest. Carriers express size limits as length + girth precisely because length alone misses the package's bulk — a 40 in long tube and a 40 in wide cube have very different girths. DimCheck sorts your three sides automatically, so you never need to figure out which measurement plays which role.
What are the length + girth limits for each carrier?
FedEx and UPS accept packages up to 165 in length + girth with a 108 in maximum longest side. FedEx charges Additional Handling above 105 in and Oversize above 130 in. USPS Priority Mail is limited to 108 in, while Ground Advantage and Parcel Select allow up to 130 in with an oversized price above 108. DHL Express sets piece limits in centimeters — 120 × 80 × 80 cm — and a 300 cm absolute maximum on the longest side.
How does rounding affect length + girth?
More than you would expect. FedEx, UPS, and USPS round every dimension up to the next whole inch before calculating, and the length + girth thresholds are checked against those rounded sides. A box measured at 40.1 × 20.1 × 12.1 in has an unrounded length + girth of 104.5 in — under FedEx's 105 in Additional Handling trigger — but the rounded sides (41 × 21 × 13 in) sum to 109 in, which crosses it. The calculator applies the rounding before the sum so the diagnosis matches the invoice.