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Field note5 min read

How to Measure Box Dimensions for Shipping

Measure the sealed outside of the package, not the empty carton or the product inside it.

Measure the finished outside dimensions

Close, tape, and pack the box before measuring. Use the longest point on each outside axis, including bulges, seams, tape, or hardware that changes the package profile.

  • Place the box on a flat surface.
  • Measure the longest side and record it as length.
  • Measure the other horizontal side as width.
  • Measure from the base to the highest point as height.
  • Keep the scale weight with the recorded dimensions.

Use length × width × height

A 16 × 12 × 10 inch box has a volume of 1,920 cubic inches. Carriers may apply their own whole-inch measurement and rounding sequence, so keep the original measurements until the label is rated.

FORMULA
Package volume = Length × Width × Height

Common measuring mistakes

MistakeWhy it matters
Using inside dimensionsShipping systems usually need the finished outside size
Measuring an unsealed cartonPacked panels can bow outward
Ignoring the longest pointAutomated dimensioners may capture the protrusion
Rounding too earlyThe carrier rule should control rounding