Free, no signup. Rules checked November 2026
FedEx dimensional weight calculator
Enter a box size to see what FedEx will bill, and whether it trips a size surcharge.
FedEx divides a package's cubic inches by 139 and bills the greater of that and the scale weight. Enter your box and weight to get the FedEx billable weight under the 2026 Service Guide, where every fraction of an inch rounds up, plus a check against the Additional Handling and Oversize limits.
FedEx dimensional weight rules for 2026
From the FedEx Service Guide effective January 5, 2026, as updated September 11, 2026.
| Divisor | 139 for Express, Ground, Home Delivery, Ground Economy and international packages. |
|---|---|
| Rounding dimensions | Any fraction of an inch rounds up to the next whole inch. This has applied since August 18, 2025. |
| Rounding weight | Any fraction of a pound rounds up to the next whole pound. |
| Where it applies | Every shipment in your own packaging. There is no minimum size below which DIM weight is skipped. |
| Exempt | FedEx One Rate, which is flat-rate pricing in FedEx packaging on Express services, up to 50 lb for boxes. |
| Irregular shapes | Measured as if enclosed in a rectangular box, at the longest points. |
FedEx size surcharges a DIM calculator should warn you about
Past certain sizes FedEx adds a fee and a minimum billable weight, which can matter more than DIM weight itself.
Additional Handling: dimensions
Applies when the longest side is over 48 inches, the second-longest is over 30 inches, length plus girth is over 105 inches, or the box is over 10,368 cubic inches. The package is then billed at a minimum of 40 lb. The 2026 guide lists the fee at $29.50 to $40.75 by zone.
Additional Handling: weight
Applies over 50 lb actual weight on US shipments. The 2026 guide lists it at $46 to $58.75 by zone.
Oversize
Applies over 96 inches long, over 130 inches in length plus girth, over 17,280 cubic inches, or over 110 lb. The package is billed at a minimum of 90 lb, and the 2026 fee is $255 to $330 by zone.
Over the limits
FedEx Ground does not accept packages over 108 inches long, over 165 inches in length plus girth, or over 150 lb. One that gets into the network is charged $1,875.
The rounding rule most calculators still get wrong
Until August 2025 FedEx rounded each side to the nearest inch. It now rounds every fraction up.
What changed
A side that measures 12.1 inches used to count as 12. It now counts as 13. On a 12.1 × 12.1 × 12.1 inch box, that moves the volume from 1,728 to 2,197 cubic inches and the DIM weight from 13 lb to 16 lb.
Why you still see the old rule
Some pages, including an older FedEx explainer, still say to round to the nearest inch. The Service Guide is what FedEx bills from, and it says up.
What to do about it
Measure boxes after they are packed and taped. A carton that bulges an eighth of an inch past a whole number is billed at the next inch.
How girth is measured
Girth is twice the width plus twice the height. Length plus girth is what the 105, 130 and 165 inch limits are measured against.
FedEx billable weight examples
Each row is what this calculator returns for that box under FedEx's 2026 rules.
| Box | Billable weight | Why |
|---|---|---|
| 12×12×12 in, 5 lb 1,728 in³ | 13 lb | A one cubic foot box bills at 13 lb however light it is. |
| 12.1×12.1×12.1 in, 5 lb 2,197 in³ | 16 lb | A tenth of an inch over on each side adds 3 lb. |
| 18×14×8 in, 20 lb 2,016 in³ | 20 lb | A dense box bills at its scale weight. |
| 50×8×8 in, 12 lb 3,200 in³ | 40 lb | Over 48 inches long, so Additional Handling sets a 40 lb minimum. |
| 32×24×24 in, 30 lb 18,432 in³ | 133 lb | Over 17,280 cubic inches, so it is Oversize. DIM weight is already above the 90 lb minimum. |
How to calculate FedEx dimensional weight
Three steps. The calculator above does all of them as you type.
Step 1
Measure and round up
Measure length, width and height at the widest points and round each up to the next whole inch.
Step 2
Multiply, then divide by 139
Multiply the three rounded numbers for cubic inches, divide by 139, and round up to the next pound. That is the DIM weight.
Step 3
Take the greater weight
Compare DIM weight with the scale weight rounded up to the next pound. FedEx bills the greater, or the surcharge minimum if one applies.
FedEx dimensional weight FAQs
- What is the FedEx DIM divisor in 2026?
- 139 for US and international packages on Express, Ground, Home Delivery and Ground Economy. Multiply length × width × height in inches, divide by 139, and round up to the next pound.
- Does FedEx round dimensions up or to the nearest inch?
- Up. Since August 18, 2025 the FedEx Service Guide says any fraction of an inch is rounded up to the next whole inch, so 12.1 inches is billed as 13. Before that date FedEx rounded to the nearest inch.
- Does FedEx Ground use dimensional weight?
- Yes. FedEx applies dimensional weight to all Ground and Home Delivery packages in customer packaging, at the same 139 divisor as Express. There is no size below which it is skipped.
- Does FedEx One Rate use dimensional weight?
- No. One Rate is flat-rate pricing for FedEx Express services in FedEx-branded packaging, so the price depends on the packaging and distance, not DIM weight. Boxes and tubes can weigh up to 50 lb and envelopes up to 10 lb.
- When does the FedEx Additional Handling surcharge apply?
- When the longest side is over 48 inches, the second-longest side is over 30 inches, length plus girth is over 105 inches, the box is over 10,368 cubic inches, or it weighs over 50 lb. Packages that trigger it on size are billed at a minimum of 40 lb.
- What is the maximum size FedEx will ship?
- Up to 150 lb, 108 inches long for Ground and Home Delivery, and 165 inches in length plus girth. Express services allow up to 119 inches long. Larger shipments go by FedEx Freight.
- Can I get a better FedEx DIM divisor?
- Possibly. The 139 here is the published divisor. High-volume shippers can ask FedEx for a higher divisor in their contract, and a higher divisor lowers DIM weight.
Compare with other carriers
The same box can bill at a different weight depending on who carries it.
- All carriers side by sideUPS, FedEx and USPS billable weight for one box, in one table.
- UPS Dimensional Weight CalculatorUPS DIM and billable weight at ÷139 (daily) and ÷166 (retail), plus Additional Handling and Large Package checks.
- USPS Dimensional Weight CalculatorUSPS DIM and billable weight at the 139 divisor in effect since July 12, 2026, with the one cubic foot rule and nonstandard-fee checks.
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