Dimensional Weight Calculator
Free dimensional weight calculator: enter dimensions and actual weight to get DIM weight and billable weight instantly. Supports express (5000 / 139) and air freight (6000 / 166) divisors, multiple packages, and one-click metric/imperial switching.
Express couriers commonly use 5000 (cm³/kg) / 139 (in³/lb); air freight uses 6000 / 166. A smaller divisor gives a larger dim weight.
Enter your freight rate to estimate cost from the billable weight.
Weights and cost are estimates for reference only. Actual billing follows your carrier’s published rules.
How dim weight is calculated
The formula is one line: dim weight = length × width × height ÷ dimensional factor. Measure in centimeters and divide by 5,000 (express) or 6,000 (air freight); measure in inches and divide by 139 (express) or 166 (air). Then compare the result with the actual weight — whichever is greater becomes the billable weight. This is the industry-wide rule for express and air cargo, not one carrier's quirk.
When do you actually pay by dim weight?
Cargo falls into two buckets: dense freight and bulky-but-light freight. The second kind — down jackets, shoe boxes, throw pillows, lamps — takes up space without weighing much, so its dim weight usually beats its actual weight, and that's what you pay on. Dense goods like books, hardware, or tiles go the other way and bill on actual weight.
Cross-border sellers get burned here most often: the product is light, the box is big, dim weight doubles, and logistics eats the margin. Always run both numbers before quoting.
Where do 5,000 / 6,000 / 139 / 166 apply?
- International express (DHL, UPS, FedEx and the like): divide centimeters by 5,000, inches by 139.
- Air freight: divide centimeters by 6,000, inches by 166.
- Ocean FCL and LCL generally bill on straight volume (CBM) — no dim-weight formula — though LCL has a minimum billable volume.
One caveat: these are industry standards, but each carrier tweaks the fine print, so check the carrier's site before you book.