RULES CURRENTNMFC density scale · Jul 19, 2025USPS DIM 139 · Jul 12, 2026Last checked Sep 24, 2026
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REFERENCE

Guides

The reference material behind the calculators: what the rules say, where the numbers come from, and how to measure freight so your bill matches your quote.

NMFC changes 2025The July 2025 density scale and what it replaced.Sep 24, 2026USPS DIM divisor 139How USPS applies DIM weight above 1 cubic foot.Sep 24, 2026Shipping container sizesInternal dimensions and real capacity, by container.Sep 24, 2026Pallet sizesStandard pallet dimensions and stacking limits.Sep 24, 2026How to measure LTL freightMeasure and weigh the way the carrier does.Sep 24, 2026