Dimensional weight calculator
Dimensional weight calculator: L × W × H divided by a carrier divisor; chargeable is the greater of actual and dimensional. FedEx 139, UPS, USPS, DHL, Amazon, IATA air and other presets live on this URL. Old per-carrier pages redirect here with ?carrier=.
Package details
DIM result
(20 × 16 × 12) ÷ 139 = 27.63 lb. Chargeable is the greater of actual 10 lb and dimensional 27.6 lb. Typical billed integer is 28 lb (ceil).
Estimate only. No live carrier rates. Confirm the current service guide and your contract divisor.
You pay on 28 lb, not 10. Shrink the carton or see chargeable weight.
Formula
- Volume = L × W × H (in³ or cm³ matching the divisor).
- Dimensional weight = volume / divisor.
- Chargeable = max(actual, dimensional).
- We show the exact quotient and a typical ceil-to-integer billed weight. Rounding rules are in the service guide, not here.
Carrier divisors
Planning values, last reviewed September 2026. Always confirm the current guide.
| Carrier | in³/lb | cm³/kg |
|---|---|---|
| FedEx | 139 | 5,000 |
| UPS | 139 | 5,000 |
| USPS | 139 | 5,000 |
| DHL Express | 139 | 5,000 |
| Amazon (FBA & Buy Shipping) | 139 | 5,000 |
| IATA air | 166 | 6,000 |
| Canada Post | 166 | 6,000 |
| Australia Post | 111 | 4,000 |
| Purolator | 139 | 5,000 |
| Parcelforce | 166 | 6,000 |
| TNT | 111 | 4,000 |
FedEx — 139 in³/lb
US domestic DIM commonly uses 139. A 20 × 16 × 12 in carton is 27.6 lb dimensional. Contract divisors can differ.
UPS — 139 in³/lb
Daily Rates typically apply DIM to every package; there is no 1 ft³ free band like USPS.
USPS — 139 in³/lb above 1 ft³
Threshold and rounding live in the DMM. Cubic foot = 1,728 in³; 12 × 12 × 12 in is the usual line.
DHL Express — 139 / 5,000
Metric lanes often bill 5,000 cm³/kg. That is harsher than classic 6,000 IATA.
Amazon — 139
Fulfillment-fee dimensional factor is commonly 139. This is not a small-parcel rate quote.
TNT — 111 / 4,000
A harsh cubic factor (250 kg/m³). Confirm the product you actually booked.
Questions
Actual is 10 lb. What do I pay on?
The default 20 × 16 × 12 in carton at divisor 139 is 27.6 lb dimensional, typical billed 28 lb. Chargeable is the greater of actual and dimensional — here you pay on 28 lb, not 10. Confirm rounding in the service guide.
Does USPS DIM this 20×16×12 box?
Volume is 3,840 in³ = 2.22 cu ft, so it is above the usual 1 cu ft (1,728 in³) USPS threshold. USPS also moved to 139 on 12 July 2026. A 12×12×12 in cube is the line; below that, actual weight often wins. Confirm the current DMM.
Can I use 139 for every carrier?
No. FedEx/UPS/DHL/Amazon planning is often 139 in³/lb or 5,000 cm³/kg. IATA air and some posts use 6,000. Australia Post / TNT are harsher (4,000). Pick the preset; contract divisors override this table.
How do I cut billed weight without changing the product?
Shrink the box. An inch off each side of 20×16×12 drops dim weight about 16%. Don’t ship air in a big carton. For a full shipment use the CBM calculator; for the billable max see chargeable weight.