Carriers charge by whichever is greater — actual weight or dimensional weight. Pick a carrier, enter your dimensions, see your true chargeable weight and estimated cost, with the Aug 2025 ceiling rounding rule applied by default.
Leave blank to use the carrier's standard divisor. High-volume shippers often negotiate divisors of 166 or 194.
Optional — your average shipping cost per kg. Used to estimate the cost for this package.
Need carrier rate sheets, historical divisor changes, or batch DIM weight processing for a spreadsheet of packages? Our sister site dimweightcalc.com goes deeper on carrier-by-carrier nuance — useful when you're modeling shipping costs for a whole catalog.
Visit dimweightcalc.com →Dimensional weight — also called "DIM weight" or "volumetric weight" — is how shippers price low-density packages. A box full of pillows weighs almost nothing, but it takes up the same trailer space as a heavy box. So carriers compute a weight from the volume, and charge you whichever is greater: actual or dimensional.
The formula is simple: DIM weight = (L × W × H) ÷ divisor. Each carrier publishes its own divisor — and different ones for domestic vs international, air vs ground. This calculator uses the current published values:
| FedEx / UPS (US) | 139 in³/lb |
| FedEx / UPS / DHL (intl) | 5,000 cm³/kg |
| USPS Priority | 166 in³/lb |
| Royal Mail | 6,000 cm³/kg |
| Air freight (IATA) | 6,000 cm³/kg |