Dimensional Weight Calculator

Dimensional weight (also called volumetric weight) is a pricing method used by carriers when a package is large but light. It is calculated as L × W × H ÷ DIM divisor. Carriers charge the higher of actual weight or DIM weight. This system incentivizes shippers to use right-sized packaging, as oversized boxes waste trailer and aircraft space.

FedEx uses a DIM divisor of 139 for both domestic and international shipments (in cubic inches per pound). In metric terms, this is equivalent to approximately 5,000 cm³/kg. UPS also uses 139 for most services. DHL Express typically uses 5,000 cm³/kg (139 in³/lb). USPS Priority Mail uses 166 in³/lb. Always verify current factors as carriers update them periodically.

Key strategies: Use right-sized boxes (no bigger than needed). Reduce void fill/dunnage — if you can use less padding, use a smaller box. Consider custom-sized packaging for high-volume products. Work with your packaging supplier to reduce box dimensions by even 1–2 inches. Negotiate DIM factors with carriers if you ship high volume — some carriers offer custom factor agreements.

DIM weight applies when a package's dimensional weight exceeds its actual weight. As a rule of thumb: if a package is larger than about 1 cubic foot (1,728 cu in) for FedEx/UPS (÷139), DIM weight may apply for lightweight items. Heavier or denser items are more likely to be billed on actual weight. Use this calculator to check before shipping.

DIM weight is the volumetric equivalent weight calculated from package dimensions. Actual weight is the physical weight on a scale. Billable weight is what the carrier charges — it is always the GREATER of actual weight or DIM weight (rounded up to the nearest pound or half-pound depending on carrier). You can only reduce your bill if the billable weight is driven by DIM (not actual) weight.