DIM Weight Calculator
Calculate dimensional weight for FedEx, UPS, USPS, and DHL. Enter your package dimensions to find the billable weight and avoid surprise shipping costs.
The Formula
Where L, W, H are in inches and the result is rounded up to the nearest pound.
Calculate DIM Weight
Calculate DIM Weight
Why DIM Weight Matters
Carriers charge based on whichever is greater: actual weight or dimensional weight. Large, lightweight packages often cost more due to DIM pricing.
- ✓FedEx and UPS use a divisor of 139 for most shipments
- ✓USPS uses a more favorable divisor of 166
- ✓DIM only applies to USPS packages over 1 cubic foot
- ✓As of August 2025, fractional inches are rounded UP before calculating
DIM Weight Divisors
| Carrier | Service | DIM Divisor | Unit | Rounding | Notes |
|---|---|---|---|---|---|
| FedEx | Ground / Home Delivery (Daily Rates) | 139 | cubic inches | up | Standard for negotiated/daily rate accounts. As of Aug 18, 2025, fractional inches round up before calculation. |
| Ground / Home Delivery (Retail Rates) | 166 | cubic inches | up | Retail/counter shipments may use 166 divisor | |
| Express (All Services) | 139 | cubic inches | up | Same divisor for all Express services. 40-lb minimum if AHS-Dimension applies. | |
| International | 139 | cubic inches | up | Or 5000 cm³/kg for metric calculations | |
| UPS | Ground (Daily Rates) | 139 | cubic inches | up | Standard for negotiated/daily rate accounts. As of Aug 18, 2025, fractional inches round up. |
| Ground (Retail Rates) | 166 | cubic inches | up | Retail shipments use 166 divisor | |
| Air (2nd Day, Next Day) | 139 | cubic inches | up | No minimum cubic threshold for air services | |
| Ground Saver (formerly SurePost) | 139 | cubic inches | up | DIM applies to qualifying packages over 1 cubic foot | |
| USPS | Ground Advantage | 166 | cubic inches | up | Only applies if package exceeds 1 cubic foot (1,728 in³) |
| Priority Mail | 166 | cubic inches | up | Flat Rate boxes exempt from DIM pricing | |
| Priority Mail Express | 166 | cubic inches | up | Flat Rate envelopes and boxes exempt | |
| DHL Express | Express (US Domestic) | 139 | cubic inches | up | Standard divisor for US domestic shipments |
| Express (International) | 139 | cubic inches | up | Or 5000 cm³/kg for metric (equivalent to 139 in³/lb) |
How to Use This Calculator
- 1Measure your package's length, width, and height in inches
- 2Enter the actual weight of your package in pounds
- 3Select the carrier you plan to use
- 4Click Calculate to see your DIM weight and billable weight
Frequently Asked Questions
What is dimensional weight?
Dimensional weight (DIM weight) is a pricing method that reflects package density. It's calculated by multiplying length × width × height and dividing by a DIM divisor. Carriers charge whichever is greater: actual weight or DIM weight.
Why do FedEx and UPS use 139 while USPS uses 166?
The lower the divisor, the higher the DIM weight and cost. FedEx and UPS use 139 for most commercial accounts, making them more expensive for lightweight, bulky items. USPS's 166 divisor is more favorable but only applies to packages over 1 cubic foot.
When does DIM weight apply?
For FedEx and UPS, DIM weight applies to all packages. For USPS, it only applies to packages exceeding 1 cubic foot (1,728 cubic inches). Flat Rate boxes are exempt from DIM pricing.
How can I reduce DIM weight charges?
Use right-sized packaging, avoid excessive void fill, consider USPS for lightweight bulky items, and ensure accurate dimension capture to avoid billing corrections.
Automate dimension capture
Stop manual measuring. Sizelabs dimensioners capture accurate package dimensions in real-time, ensuring you never overpay on shipping.