6,912 cubic inches (4 cu ft, 0.1133 m³). Often used for monitors, small furniture.
Packed lighter than this, you are billed this weight anyway.
| Carrier | Divisor | DIM weight |
|---|---|---|
| USPS | 139 | 50 lb |
| UPS (Daily Rates) | 139 | 50 lb |
| FedEx | 139 | 50 lb |
| UPS (Retail Rates) | 166 | 42 lb |
| DHL Express (International) | 5000 | 23 kg |
Stepping down to a 18 × 18 × 18 in box drops the UPS and FedEx floor to 42 lb, 8 lb less per parcel.
This box is over 1 cubic foot, so USPS applies dimensional weight.
Your box Rounded up by USPSWhole numbers, nothing rounded
Sample box shown. Type your own size and weight below; the result updates instantly.
USPS · divisor 139
Priority Mail, Priority Mail Express, Ground Advantage, Parcel Select
Billable weight
50lb
You pay for 30 lb of air on every box.
A box 1 inch smaller on every side bills 7 lb less.
| USPS | ÷139 | 50 lb |
| UPS | ÷139 | 50 lb |
| FedEx | ÷139 | 50 lb |
| UPS Retail | ÷166 | 42 lb |
| DHL Express | ÷5000 | 23 kg |
6,912 cubic inches ÷ 139 = 49.73, rounded up to 50 lb for UPS Daily Rates and FedEx. USPS also bills 50 lb since the July 2026 change.
With UPS and FedEx, anything packed under 50 lb is billed as 50 lb. Above that, you pay actual weight.
Carrier rules verified 2026-09-30. Methodology