Dimensional weight calculator
Enter the package size and weight in inches and pounds, or centimetres and kilograms. Pick the DIM divisor from your rate sheet: you get the dimensional weight and the billable weight, the greater of the two.
How to calculate dimensional weight
Billable weight = max(actual weight, DIM weight), rounded up
| Divisor | Units | Typical use | Rounding |
|---|---|---|---|
| 166 | in³ per lb | international air cargo (same as IATA 6000) | next whole lb |
| 139 | in³ per lb | many express and parcel rates | next whole lb |
| 6000 | cm³ per kg | IATA air cargo | next 0.5 kg |
| 5000 | cm³ per kg | express and courier | next 0.5 kg |
Worked example: 2 cartons, 24 × 18 × 16 in, 25 lb each
| Step | Divisor 139 (per piece) | Divisor 166 (total) |
|---|---|---|
| Cubic inches | 24 × 18 × 16 = 6,912 per carton | 6,912 × 2 = 13,824 |
| DIM weight | 6,912 ÷ 139 = 49.7 → 50 lb per carton | 13,824 ÷ 166 = 83.3 lb |
| Actual weight | 25 lb per carton | 50 lb |
| Billable weight | 50 × 2 = 100 lb | 84 lb |
Light, bulky cartons are billed on their size. The same cargo costs more under a 139 divisor than under 166: a smaller divisor gives a higher DIM weight.
From inches and pounds to the IATA rule
1 inch = 2.54 cm and 1 lb = 0.45359237 kg, so 6000 cm³ per kg equals about 366 in³ per kg, or 166 in³ per lb. That is why international air cargo quoted in pounds uses 166. For the metric version with several piece lines and LCL, use the chargeable weight calculator.
Last updated 5 October 2026. Divisors vary by carrier and service: always check your rate sheet.
From billable weight to a client quote.
QUAY prices the quote from the chargeable weight: rate per kg with a minimum, surcharges, margin or markup. Then it shares a PDF that shows your client the sell prices only. Metric units today.
Per piece or per shipment?
Express and parcel carriers usually apply DIM weight per piece and round each piece up. Air cargo compares the total actual weight with the total DIM weight of the shipment.
Why is my billable weight higher than the scale?
Because the package is large for its weight. Smaller boxes or less void fill lower the DIM weight.
Which divisor should I use?
The one printed on your carrier's rate sheet or contract. 166 and 6000 are the air cargo standards; 139 and 5000 are common for express.