Dimensional weight calculator
Enter your package size, weight and divisor to see dimensional weight, actual weight and the billable weight, using the rounding rules the carriers document. Your numbers stay in your browser.
Dimensional weight calculator
Runs entirely in your browser. Nothing you type is sent anywhere.
Carrier rules on this page are as of 2026-10-29. Carriers change their terms, and some passages could only be confirmed from search excerpts of the official pages. Where a rule is marked "check the current carrier terms", we could not confirm it. RefundDock is independent and not affiliated with UPS or FedEx. Nothing here promises any refund or amount.
How billable weight is worked out
Carriers charge on the greater of the package's actual weight and its dimensional weight. FedEx's Service Guide describes dimensional weight as length x width x height in inches, with any fraction of an inch rounded up, divided by a divisor, and says any fraction of a pound is rounded up. Source: FedEx Service Guide 2026 (effective Jan 5, 2026). As of 2026-10-29. UPS also rounds fractions of a pound up. Its inch rounding is described inconsistently across UPS documents, so the calculator above shows both methods and uses the larger dimensional weight. Source: 2026 UPS Rate & Service Guide, Daily Rates; UPS: shipping dimensions and weight. As of 2026-10-29. Confirmed from search-index excerpts of the official page; read the source before relying on it.
About the divisor
The divisor is the number that turns cubic inches into pounds. The calculator pre-fills 139 only for the UPS rule set, which is the divisor shown for Daily Rates in the 2026 UPS Rate & Service Guide. Source: 2026 UPS Rate & Service Guide, Daily Rates. As of 2026-10-29. Confirmed from search-index excerpts of the official page; read the source before relying on it. For FedEx and for anything else, no default is filled in, because we have not verified a current figure that applies to every account. FedEx invoice downloads include a Dim Divisor column; use that or your contract. Source: FedEx Billing Online invoice download data dictionary. As of 2026-10-29.
Contracts override published terms. A negotiated divisor can be higher or lower than any list figure, and using the wrong one will produce a false "overcharge". If you do not know yours, check your contract/tariff or ask your account representative.
What this calculator does not do
- Minimum billable weights. FedEx treats a package that meets an Additional Handling dimension trigger as a 40 lb minimum. Source: FedEx Service Guide 2026 (effective Jan 5, 2026). As of 2026-10-29. UPS Large Package has a 90 lb minimum. Source: 2026 UPS Tariff/Terms and Conditions of Service, United States. As of 2026-10-29. Confirmed from search-index excerpts of the official page; read the source before relying on it. These are not applied automatically, so a billed weight above the result may be legitimate.
- Dollars. It does not look up rates. Rates depend on your contract and zone.
- Metric units. Use inches and pounds.
- Special pricing. Flat-rate packaging and multiweight or hundredweight pricing work differently.
What to do if your billed weight is higher
A gap is a reason to look, not a conclusion. Work through these in order:
- Confirm the dimensions on the invoice. They may be the carrier's measurement, not yours.
- Confirm the divisor on the invoice against your contract.
- Check for a minimum billable weight tied to a surcharge.
- If a difference remains, gather your packed dimensions, scale reading and photos for that shipment, and ask the carrier to explain. Carriers can audit and adjust dimensions and weight after the fact, so your evidence is what counts. Source: FedEx Service Guide 2026 (effective Jan 5, 2026). As of 2026-10-29.
Billing disputes have a 180-day window at both carriers, so do not wait. See the overcharge checklist for the other checks.
Frequently asked questions
What is dimensional weight?
A weight derived from a package's size: length x width x height in inches, divided by a divisor, with fractions rounded up. Carriers bill the greater of dimensional and actual weight.
Which divisor should I use?
The one in your carrier agreement or on your invoice. The calculator pre-fills 139 for UPS only (the UPS Daily Rates figure) and leaves other carriers blank. Check your contract/tariff.
Does the calculator send my data anywhere?
No. It runs as JavaScript in your browser and nothing is transmitted or stored.
Why might my invoice show a higher weight than the calculator?
A different divisor, carrier-measured dimensions, a minimum billable weight, or special packaging or pricing rules can all explain it. It is a prompt to check, not proof of an error.
Free audits are not open yet. They open at launch.
Our fee is 20% of credits the carrier actually applies to your account. If there are no credits, you pay nothing.