DimWeight Calc › FedEx
FedEx dimensional weight calculator
FedEx bills the greater of the package’s actual rounded weight and its dimensional weight. Enter the box and see the billable weight, per piece or per shipment.
Calculations run entirely in your browser – the sizes and weights you type are never sent to a server.
FedEx dimensional weight rules
FedEx Express, Ground, Home Delivery & international (US Service Guide)
| Formula | L × W × H (in) ÷ 139 = lb |
|---|---|
| Rounding | Any fraction of an inch rounded up to the next whole inch; any fraction of a pound rounded up to the next pound. Billed on “the greater of the package’s actual rounded weight or dimensional weight”. |
| Applies to | All customer packaging; FedEx packaging “may” apply. US, international and US–Puerto Rico per package or per shipment; Ground and Home Delivery per package. |
| Effective | Service Guide 2026 effective Jan 5, 2026 (updated Sep 11, 2026); rounding each side up to the next inch effective Aug 18, 2025. |
- FedEx’s explainer page (F2) still says “nearest whole inch”; the Service Guide 2026 (F1, footnote 4) says any fraction of an inch is rounded up to the next whole inch, effective Aug 18, 2025. Default: Service Guide (research notes 1.2 #2). You can switch to nearest.
- FedEx Express can bill per shipment (total volume ÷ 139), which can differ by 1 lb from per-piece. Default: per piece.
Sources (checked ):
FedEx International Deferred Freight
| Formula | L × W × H (in) ÷ 166 = lb |
|---|---|
| Rounding | Same as other FedEx services. |
| Applies to | Only FedEx International Deferred Freight. |
| Effective | Service Guide 2026 (effective Jan 5, 2026). |
- Service Guide p.135 footnote 3.
- FedEx’s explainer page (F2) still says “nearest whole inch”; the Service Guide 2026 (F1, footnote 4) says any fraction of an inch is rounded up to the next whole inch, effective Aug 18, 2025. Default: Service Guide (research notes 1.2 #2). You can switch to nearest.
Sources (checked ):
FedEx UK publishes a cm/kg rule (L × H × W ÷ 5,000 per piece) in its 2023 rate guide [F3] and explainer [F4]; the 2026 version was not verified, so use the DHL/express or Custom divisor option for metric FedEx accounts.
Worked example
- Box 15.1 × 10 × 6 in, 3 lb. Any fraction of an inch rounds up: 16 × 10 × 6 = 960 in³.
- 960 ÷ 139 = 6.91 → 7 lb billable.
- Three 10 × 10 × 10 in boxes: per piece 8 lb × 3 = 24 lb; per shipment 3,000 ÷ 139 = 21.58 → 22 lb.
FAQ
What divisor does FedEx use?
The FedEx Service Guide 2026 uses 139 for US, international and US–Puerto Rico shipments, and 166 for FedEx International Deferred Freight.
Does FedEx round up dimensions?
The Service Guide (effective Aug 18, 2025) rounds any fraction of an inch up to the next whole inch. An older FedEx page still says “nearest whole inch”; you can switch rounding in the calculator.
Per piece or per shipment?
FedEx Express can apply dimensional weight per package or per shipment; Ground and Home Delivery are per package. The calculator defaults to per piece.
Does dimensional weight apply to FedEx packaging?
It applies to all customer packaging; the Service Guide says it may also apply to FedEx packaging.