What is dimensional weight?
Dimensional (or volumetric) weight is a way to relate a package's size to a notional weight. A carrier may compare that figure with actual scale weight and price the shipment using the higher amount. The exact method is service-specific.
Basic formula
For metric measurements, a common form is: length × width × height in centimetres ÷ a carrier divisor = volumetric kilograms. For inch measurements, a service may divide cubic inches by an imperial divisor to estimate pounds. Use the divisor and units stated by your carrier; do not mix a metric divisor with cubic inches.
Example
A 30 × 20 × 15 cm parcel has a volume of 9,000 cm³. With a divisor of 5,000, the size-based estimate is 1.8 kg. If its scale weight is 1.2 kg, a service applying the greater-of rule may bill by the size-based figure before its own rounding and minimums.
How to estimate it
- Measure the outside of the fully packed parcel at its widest points.
- Choose the dimension unit and matching divisor from the carrier's service rules.
- Enter the scale weight in the matching weight unit.
- Compare the estimate with the carrier quote and check rounding or minimum billable weight.
Why this is only an estimate
Carriers may measure packages differently and can apply service-specific divisors, rounding, minimums, remote-area charges, fuel surcharges, and other fees. The calculator is not connected to carrier rates. Confirm the result with the carrier before purchasing a label.