UPS and FedEx billable weight: how the rules differ
Last updated October 28, 2026
UPS and FedEx both bill the greater of actual weight and dimensional weight, but the divisor, rounding and wording are not identical, and your own account terms can override the published rules. This guide lays out what the public pages say and where they disagree, so you know what to check in your own paperwork.
UPS
- Daily Rates: divisor 139 for domestic and international shipments. Each dimension is rounded up to the next whole inch (minimum 1 inch). The dimensional weight is rounded up to the next whole pound. Billable weight is the greater of actual and dimensional weight.
- Retail Rates: the Retail Rate & Service Guide uses 166 for domestic packages and 139 for export, with the same rounding as Daily Rates.
- Which of the two applies depends on how you ship (for example, with or without a UPS account and which rate guide your shipment is under). Ask UPS or read your invoice if you are not sure.
FedEx
- The FedEx explainer page gives a divisor of 139 and describes rounding each dimension to the nearest whole inch.
- The FedEx Service Guide, which is the contract document, says fractions are rounded up.
- These two FedEx documents disagree on rounding. If your boxes land near a boundary, the choice can move the DIM weight by a pound. Follow your own agreement, or ask your FedEx representative.
Side by side
| UPS Daily | UPS Retail | FedEx | |
|---|---|---|---|
| Divisor | 139 | 166 domestic / 139 export | 139 |
| Dimension rounding | Up | Up | Explainer: nearest inch. Service Guide: up. |
| DIM weight rounding | Up to whole lb | Up to whole lb | Check your agreement |
A quick check, step by step
- Measure the packed box and round each side the way your agreement says (round up if you are unsure; it is the safer estimate).
- Multiply the three numbers.
- Divide by the divisor for your service and round the result up to a whole pound.
- Compare with the actual weight. The larger one is the billable weight.
- Do the calculation for both divisors if you do not know which applies. For example, a 20 × 15 × 10 in box is 3,000 cu in: 3,000 ÷ 139 = 21.6, so 22 lb, and 3,000 ÷ 166 = 18.07, so 19 lb. The gap shows why it matters which rate guide your shipment falls under.
These are published carrier rules as we read them, not a quote and not tax, customs or legal advice. Treat any figure you derive as an estimate and compare it with your invoice. Dimloom lets you pick a divisor, shows the rounding it applied, and keeps your rates on your own device.
Sources
- UPS, "Shipping dimensions and weight": https://www.ups.com/us/en/support/shipping-support/shipping-dimensions-weight (read 2026-10-27 as a search-index excerpt; ups.com blocks automated fetching)
- UPS, 2026 Daily Rate & Service Guide (PDF): https://assets.ups.com/adobe/assets/urn%3Aaaid%3Aaem%3A356d938a-4f0a-4c71-b50e-bdd890f50b47/original/as/daily-rates-us-en.pdf (read 2026-10-27 as a search-index excerpt)
- UPS, 2026 Retail Rate & Service Guide (PDF): https://assets.ups.com/adobe/assets/urn:aaid:aem:47caed8a-c6fe-41e9-b98f-63f89d3d3f6c/original/as/retail-rates-us-en.pdf (read 2026-10-27 as a search-index excerpt)
- FedEx, "What is dimensional weight?": https://www.fedex.com/en-us/shipping/packaging/what-is-dimensional-weight.html (read 2026-10-27)
- FedEx, Service Guide 2026 (PDF): https://www.fedex.com/content/dam/fedex/us-united-states/services/Service_Guide_2026.pdf (read 2026-10-27 as a search-index excerpt)
Related tool: Dimloom. Estimates and guidance only; check the source documents before relying on a figure.