How to use this calculator
- Enter or choose units.
- Enter or choose length.
- Enter or choose width.
- Enter or choose height.
- Enter or choose carrier’s dimensional divisor.
- The chargeable weight updates as you type. Use Copy result or Share to keep it.
Method
Dimensional weight = L × W × H ÷ Divisor; Chargeable weight = max(Dimensional, Actual)
- L, W, H
- outside dimensions of the parcel
- Divisor
- set by the carrier, in cm³/kg or in³/lb
Worked example
- Volume = 40 × 30 × 25 = 30,000 cm³.
- Dimensional weight = 30,000 ÷ 5000 = 6 kg.
- Chargeable = the higher of 6 kg and 4.5 kg = 6 kg.
The parcel is billed at 6 kg, its dimensional weight, not its 4.5 kg actual weight.
What the result means
If dimensional weight wins, a smaller box or less void fill saves money. Right-sizing the carton is often cheaper than lighter packaging.
Assumptions and limits
- Dimensions are the outside measurements of the packed parcel.
- Carriers usually round dimensions and weights up (for example to the next whole cm or 0.5 kg), and some apply different rules above size limits. Apply your carrier’s rounding rules.
Questions
Why do divisors differ?
Each carrier sets its own density threshold. A smaller divisor gives a higher dimensional weight, so compare like with like.
Do I measure the bulges?
Yes. Measure the longest point on each side, including any bulge, as carriers do.