FedEx factor checked September 2026
FedEx Dimensional Weight Calculator
Calculate package DIM weight with the FedEx-published 139 in³/lb factor, then compare it with actual package weight.
Calculate FedEx dimensional weight
Verify the exact service and current carrier rules before rating a shipment.
Dimensions are in inches; weight results are in pounds.
Preset values are convenience defaults. Use Custom if your rate/service specifies a different factor.
Package volume-
DIM weight per package-
Total DIM weight-
Total actual weight-
Comparison weight per package-
Estimated billable comparison total-
Calculator results are comparisons, not freight quotes. Apply the carrier's current rounding, eligibility, size, surcharge and contract rules.
FedEx formula
FedEx publishes a 139 divisor.
FedEx's U.S. guidance says to multiply length × width × height in inches and divide by 139 for U.S., Puerto Rico and international shipments. Its guidance also instructs shippers to measure package dimensions to whole inches before calculation.
FedEx DIM weight = L × W × H ÷ 139For a 20 × 16 × 12 inch box: 3,840 ÷ 139 = about 27.63 lb before applicable FedEx rounding and rating rules.
Official reference: FedEx - What is Dimensional Weight?