DIM Weight Calculator

What is DIM Weight?

Dimensional weight (also called DIM weight or volumetric weight) is a pricing method used by UPS, FedEx, USPS, and DHL. Instead of charging based on actual scale weight alone, carriers charge for the space a package occupies in their trucks and planes. If your package is large relative to its weight, DIM weight will likely be higher than actual weight - and you pay for whichever is greater.

This matters because truck and aircraft space is a finite, expensive resource. A box of styrofoam and a box of steel bolts can weigh the same on a scale, but the styrofoam takes up far more room. DIM pricing corrects for this by factoring volume into the rate.

DIM Weight Formula

DIM Weight = (Length x Width x Height) / DIM Divisor

The divisor varies by carrier and unit system. UPS and FedEx use 139 for domestic shipments measured in inches. USPS uses 166 but only applies DIM weight to Priority Mail packages over one cubic foot (1,728 cubic inches) - smaller packages are exempt. DHL Express international uses 139 for inches or 5,000 for centimeters. The result is always rounded up to the next whole pound.

Example: A 16x12x8 inch box has a volume of 1,536 cubic inches. Divided by 139, that gives a DIM weight of 11.1 lbs - rounded up to 12 lbs. If the actual package weighs 8 lbs, UPS and FedEx will bill 12 lbs.

Which Weight Gets Charged?

You are always billed for the greater of actual weight or DIM weight. For most small, dense packages (hardware, books, heavy goods), actual weight will be higher. For large, light packages - clothing, bedding, foam products, air-filled packaging - DIM weight is almost always higher, sometimes 2-4x the scale weight.

How to Reduce DIM Weight Charges

• Use the smallest box that safely fits your product - every extra inch adds up
• Switch to poly mailers for soft goods like clothing and fabric items
• Reduce excess void fill that inflates package size without protecting the contents
• Use USPS for packages under one cubic foot where DIM weight does not apply
• Consider flat-rate boxes for heavy, dense items shipping long distances
• Negotiate a custom DIM divisor with your carrier rep - high-volume shippers often qualify for 166 or higher