Dimensional Weight Calculator
Find shipping dimensional (volumetric) weight.
Carriers bill the greater of actual and dimensional weight for bulky parcels.
How the Math Works
The Dimensional Weight Calculator uses the formula DIM weight = L × W × H ÷ divisor to determine volumetric weight. This calculation multiplies the length, width, and height of your package (in inches) to find its volume, then divides by a carrier-specific divisor (typically 166 for domestic U.S. shipments). The divisor converts cubic inches to an equivalent weight in pounds, accounting for how much space a package occupies relative to its actual weight. Carriers use this because lightweight, bulky items take up significant trailer space but generate less revenue from actual weight charges.
Practical Applications
To use this calculator, measure your package's longest dimensions in inches for length, width, and height, then enter these values along with your carrier's divisor. For example, a box measuring 12 × 10 × 8 inches with divisor 166 yields a DIM weight of 5.78 pounds. Compare this calculated value against the package's actual weight - whichever is greater determines your shipping cost. This is essential when shipping items like pillows, clothing, or electronics where volumetric weight often exceeds actual weight.
Day-to-Day Use
Understanding dimensional weight helps you save money on everyday shipping, whether you're sending holiday gifts, online purchases, or business documents. By calculating this before shipping, you can choose appropriately sized boxes to reduce costs, or realize when an item's light weight makes it expensive to ship due to space requirements. This knowledge empowers smarter packaging decisions, potentially saving $5-20 per shipment on common e-commerce deliveries.
Worked example
20×16×12 in ÷ 139 → ~27.6 lb.
FAQ
Which weight is billed?
The larger of actual weight and DIM weight.