Dimensional weight calculator
A DIM weight calculator answers: would this box price as if it were heavier than the scale says? Enter inches, pick a typical divisor, and see the dimensional weight carriers may use.
Dimensional weight calculator
DIM weight = length × width × height ÷ divisor, then rounded up. Divisors and thresholds vary by carrier and service — use this as a planning number, then compare live rates.
- Cubic inches
- 1,680
- Divisor used
- 166
- DIM weight
- 11 lb
This package is 1 cubic foot or smaller. USPS often ignores DIM on many services until you exceed that size.
The formula
Dimensional weight (pounds) = ceil(length × width × height ÷ divisor). Inches for all sides. USPS commonly uses 166 and often applies DIM when the package is larger than 1 cubic foot (1,728 cubic inches). UPS daily rates often use 139; some retail UPS prices use 166. Always treat these as planning defaults.
Why empty space is expensive
Carriers have to move air if you ship air. A 8 oz shirt in a 14×12×10 box can bill as a much heavier parcel. The fix is usually a smaller box or a poly mailer — not a cheaper brand of tape. More context: how dimensional weight works.
After you have DIM weight
Compare it to actual packed weight. The higher number is usually billable. Then compare current shipping rates — the live quote applies the carrier’s current rule, which is the source of truth.
Keep reading
Frequently asked questions
Ready to ship?
Use this DIM number when you compare live rates.