Package Girth Calculator

Girth is the distance around the two shorter sides of a package — calculated as 2 × (width + height), assuming length is the longest side. Carriers use "length + girth" as a single combined number to flag oversized packages that need special handling, regardless of actual weight.

Major US carriers commonly apply additional fees or size restrictions once length + girth exceeds 130 inches, and refuse shipment altogether beyond about 165 inches (limits vary by carrier and service level, and change over time) — always verify current thresholds with your specific carrier before shipping an unusually large box.

Example: a box measuring 20 × 10 × 8 in has a girth of 36 in (2 × (10 + 8)), for a length + girth total of 56 in (20 + 36) — comfortably under typical oversize thresholds.

Girth exists because handling difficulty is not captured by weight. A long thin tube and a compact cube can weigh the same while needing completely different equipment and conveyor clearance, so carriers combine the longest side with the wrap-around measurement of the other two to produce one number that flags awkward freight.

There are usually three separate thresholds, not one. Carriers commonly apply an additional-handling charge from around 105 inches of length plus girth, a large-package or oversize charge above about 130 inches, and an outright limit near 165 inches, alongside a separate maximum length of roughly 108 inches. A parcel can breach the length limit while passing the combined figure.

Oversize charges are usually assessed as a minimum billable weight rather than a flat fee, which is why they hit so hard. A large-package surcharge often forces the shipment to bill at a set minimum — frequently around 90 lb — regardless of what the box actually weighs, so a light but bulky item can cost several times its normal rate.

Sort your dimensions before entering them, because the formula assumes length is the longest side. Measuring girth around the wrong pair of sides understates the total and can turn a shipment you believed was compliant into a surcharge at the depot, where carriers measure automatically.

Verify current thresholds before shipping anything unusual. Published limits differ between carriers and between ground, air, and freight services, and they are revised periodically — furniture, rugs, skis, tubes, and long cartons are the categories where the numbers matter most and where refusal at drop-off is a real risk.

Verify current published limits with your carrier before shipping furniture, tubes, or long cartons.