FedEx dimensional weight calculator
FedEx bills a package on the greater of its actual weight and its dimensional weight: length × width × height in inches ÷ 139. Since 18 August 2025 any fraction of an inch is rounded up to the next inch, and any fraction of a pound is rounded up to the next pound.
- Divisor
- 139 in³/lb (FedEx International Deferred Freight: 166)
- Each side
- Any fraction of an inch rounded up to the next inch, since 18 August 2025
- Weight
- The greater of actual and dimensional weight, any fraction of a pound rounded up
- Applies to
- All shipments in customer packaging; may apply to FedEx packaging
- Per
- Package for FedEx Ground and Home Delivery; package or shipment for other services
- Minimums
- 40 lb with the Additional Handling Surcharge (dimension), 90 lb with the Oversize Charge (US)
- Source
- FedEx Service Guide 2026, pp. 126–128 and 135
The FedEx rule, step by step
- Measure the length, width and height of the package on the outside.
- Round any fraction of an inch up to the next inch: 12.1 in counts as 13.
- Multiply the three sides and divide by 139. Round any fraction of a pound up.
- Compare with the actual weight, also rounded up to the next pound. The greater one is the billable weight.
What rounding each side up costs
| Package | Sides as measured | FedEx: each side rounded up |
|---|---|---|
| 12.4 × 10.3 × 8.2 in, 5 lb | 1,047.3 in³ ÷ 139 = 7.53 → 8 lb | 13 × 11 × 9 = 1,287 in³ ÷ 139 = 9.26 → 10 lb |
| 16.2 × 12.1 × 10.4 in, 9 lb | 2,038.61 in³ ÷ 139 = 14.67 → 15 lb | 17 × 13 × 11 = 2,431 in³ ÷ 139 = 17.49 → 18 lb |
| 20 × 16 × 12 in, 30 lb | 3,840 in³ ÷ 139 = 27.63 → 30 lb | 20 × 16 × 12 = 3,840 in³ ÷ 139 = 27.63 → 30 lb |
Fractions add up on every side. The 12.4 × 10.3 × 8.2 in package would be 8 lb from its exact volume, but FedEx bills it as 13 × 11 × 9 in: 10 lb. A box that is a few tenths over a whole inch on each side is worth measuring again, or replacing with one that is exactly on the inch. The last row is dense enough that its 30 lb scale weight is billed either way.
Open these packages in the calculator
Large packages: 40 lb and 90 lb minimums
When a package triggers a large-package charge, FedEx also bills it at a minimum weight, whatever the scale and the dimensional weight say:
| Charge (US package services) | When the package measures more than | Minimum billable weight |
|---|---|---|
| Additional Handling Surcharge (dimension) | 48 in on the longest side, 30 in on the second-longest, 105 in in length plus girth, or 10,368 in³ | 40 lb |
| Oversize Charge | 96 in on the longest side, 130 in in length plus girth, or 17,280 in³ | 90 lb (not for international shipments) |
Length plus girth is the longest side plus twice the width plus twice the height. A 49 × 10 × 6 in package weighing 8 lb has a dimensional weight of 21.15 lb, so it would bill 22 lb; its longest side is over 48 in, so the Additional Handling Surcharge (dimension) applies and it bills 40 lb, plus the surcharge. A 60 × 30 × 20 in package (160 in length plus girth) falls under the Oversize Charge: 259 lb dimensional weight, so its 90 lb minimum is already met. The calculator above flags both cases; the multi-carton calculator leaves surcharges and minimums out.
Several packages: per package or per shipment
FedEx Ground and FedEx Home Delivery apply dimensional weight to each package. Other services can apply it per shipment: the volumes of all pieces are added, then divided by 139. FedEx Express multiple-piece shipments can also be rated on total shipment weight (Multiweight) when the shipment weighs 100 lb or more (200 lb for FedEx Express Saver), with a 15 lb average minimum per package; you are billed the lower of the Multiweight rate and the sum of the individual package prices. Work out the per-package figure first with the multi-carton calculator, then compare it with your Multiweight quote. How to calculate dimensional weight for multiple boxes shows why adding up totals first gives a different answer.
Cartons measured in centimetres
Convert first, then round up: 40 × 30 × 25 cm is 15.75 × 11.81 × 9.84 in, billed as 16 × 12 × 10 in = 1,920 in³ ÷ 139 = 13.81 lb, so 14 lb against 4 kg (8.82 lb) on the scale. Choose centimetres and kilograms in the calculator above and it converts for you.
What this does not cover
- Surcharge amounts, fuel surcharges, residential and delivery area charges, and prices.
- FedEx One Rate and the minimum billable weights for FedEx packaging.
- FedEx International Deferred Freight (÷ 166), freight handling units, and FedEx services outside the US, which have their own guides.
Sources
FedEx Service Guide 2026: p. 135 (dimensional weight and rounding), pp. 126–128 (Additional Handling Surcharge and Oversize Charge), p. 42 (Multiweight), and the rate pages (fractions of a pound). Checked 28 October 2026.
Related
Last updated: 28 October 2026. Billable weight only: surcharges, minimum charges and your negotiated rates are not included.