Dimensional weight calculator: UPS, FedEx, USPS
Divisors and rounding rules from www.ups.com, www.fedex.com and pe.usps.com, fetched 2026-10-14. Contract accounts may have a negotiated divisor — enter it under “Custom divisor”.
Result
The URL updates as you type, so you can bookmark or share a scenario.
Rules used
| Carrier | Divisor | Dimension rounding | When DIM applies |
|---|---|---|---|
| UPS (Daily Rates) | 139 | Nearest whole inch | All packages |
| UPS (Retail Rates) | 166 | Nearest whole inch | All packages |
| FedEx (U.S. & international) | 139 | Nearest whole inch | All packages |
| USPS Ground Advantage / Priority Mail | 139 | Up to whole inch | Only above 1,728 in³ (1 cubic foot) |
All three round the DIM weight up to the next whole pound and bill the greater of actual and dimensional weight. USPS Cubic pricing and flat-rate boxes follow different rules.
Sources
| Source | URL | Fetched | Notes |
|---|---|---|---|
| ups_dim | https://www.ups.com/us/en/support/shipping-support/shipping-dimensions-weight | 2026-10-14 | UPS: dimensional weight = L × W × H ÷ divisor; round each measurement to the nearest whole inch; increase any fraction of DIM weight to the next whole pound. Divisor 139 for Daily Rates, 166 for Retail Rates. |
| fedex_dim | https://www.fedex.com/en-us/shipping/packaging/what-is-dimensional-weight.html | 2026-10-14 | FedEx: L × W × H in inches, each rounded to the nearest whole inch, divided by 139 for U.S., Puerto Rico and international shipments; billed on the greater of dim or actual weight. |
| usps_dim | https://pe.usps.com/text/dmm300/283.htm | 2026-10-14 | USPS DMM 283 §1.4 (Ground Advantage, same rule in 223 §1.4 for Priority Mail), effective 7-12-26: round each dimension up to the whole inch; if L × W × H exceeds 1,728 in³, divide by 139 and round up; billed on the greater of actual or dimensional weight. |
Fees and rules change. Confirm against the official page and your own account before pricing decisions.
FAQ
What is the dimensional weight divisor for UPS and FedEx?
139 for FedEx U.S. and international shipments and for UPS Daily Rates; UPS Retail Rates use 166.
Does USPS use dimensional weight?
Only for parcels larger than 1 cubic foot (1,728 cubic inches). Since July 12, 2026, USPS rounds each dimension up to the whole inch and divides by 139 for Ground Advantage and Priority Mail.