Dimensional Weight Calculator
Calculate DIM weight, billable weight, and estimated cost for UPS, FedEx, USPS, and DHL — with the 2026 carrier divisors and the latest dimension-rounding rule built in.
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Drag to rotate · box scales to your dimensions
- Cubic size —
- Dimensional weight —
- Actual weight —
- Total — 1 pkg —
Estimates for planning. Divisors, thresholds, and rounding vary by carrier, service, and contract — confirm with your carrier before shipping.
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Dimensional weight calculator for UPS, FedEx, USPS & DHL
This free dimensional weight calculator (also called a DIM weight or volumetric weight calculator) shows the billable weight carriers actually charge you for. Because parcel carriers price by the space a box occupies, a light but bulky package is often billed at its dimensional weight rather than its scale weight — quietly inflating shipping cost on every order. Enter your box size above to see the DIM weight, the chargeable weight, and an optional cost estimate in inches/lb or cm/kg.
How to calculate dimensional weight
- Measure the box. Record length, width, and height. For UPS and FedEx, round each dimension up to the next whole inch.
- Find the cubic size. Multiply length × width × height to get the volume in cubic inches (or cubic centimeters).
- Divide by the DIM divisor. Use 139 for UPS/FedEx, 166 for USPS, or 5000 for metric to convert volume into dimensional weight.
- Compare to actual weight. Weigh the packed box and compare the scale weight to the dimensional weight.
- Bill the greater. The carrier charges whichever is higher, rounded up to the next whole pound — that is your billable weight.
DIM weight = (L × W × H) ÷ DIM divisorDIM divisors by carrier
The DIM divisor (or DIM factor) converts cubic size into weight. A higher divisor means a lower dimensional weight — and a lower bill for the same box.
| Carrier / service | Divisor (inches) | Metric (cm) | Notes |
|---|---|---|---|
| UPS — Domestic US | 139 | 5000 | Rounds each dimension up to the next inch |
| FedEx — Domestic US | 139 | 5000 | Cubic pricing for small dense parcels |
| USPS — Priority | 166 | — | Only applies over 1 cu ft (1,728 in³) |
| DHL Express | 139 | 5000 | Mostly international |
| International courier | — | 5000 | Standard metric divisor |
| Air freight | — | 6000 | Standard air cargo |
| LTL freight | 194 | — | Density-based pricing |
Divisors and rules can change and vary by service and contract. High-volume shippers can sometimes negotiate a higher divisor (for example 166 instead of 139), which lowers DIM weight on every shipment. Always confirm with your carrier.
Dimensional weight example
A box measuring 20 × 16 × 10 in has a cubic size of 3,200 in³. Dividing by the UPS/FedEx divisor of 139 gives a dimensional weight of 23.0 lb (rounded up to 24 lb). If the packed box actually weighs only 5 lb, the carrier still bills the higher figure — so you pay for 24 lb, not 5 lb.
The same box at the USPS divisor of 166 would be about 19.3 lb — a clear example of why the divisor and carrier choice matter for bulky, lightweight shipments.