Parcel shipping · Free · No sign-up
Dimensional Weight Calculator
Work out the dimensional weight, the billable weight and the girth of a parcel for UPS, FedEx or USPS. The calculator applies the whole-inch round-up all three carriers now use, and the USPS one-cubic-foot threshold that stops small boxes being rated on volume.
- Free · no sign-up
- UPS · FedEx · USPS
- Whole-inch round-up
- Custom divisor
- Girth & oversize
Dimensional weight and billable weight calculator
Enter the package dimensions and weight to see the billable weight.
Billable weight
— lb
—
- Dimensional weight
- —
- Actual weight
- — lb
- Divisor
- —
- Billed dimensions
- —
- Cubic inches
- —
- As measured
- —
Rounding changed your volume. Your measured dimensions (—) were rounded up to — before the calculation, because every fraction of an inch rounds up to the next whole inch.
Under the USPS threshold. This package is one cubic foot (1,728 in³) or smaller, so USPS rates it on actual weight and dimensional weight does not apply.
Figures are indicative. Confirm divisors, thresholds and surcharges with your carrier before booking.
Oversize
Girth and length-plus-girth
Girth is the distance around the package at its thickest point, measured across the two smaller sides. Carriers add it to the longest side to decide whether a parcel is oversized. The figures below update with the dimensions you entered above, using the longest side as the length — which is how carriers measure it, whichever field you typed it into.
- Longest side
- — in
- Girth
- — in
- Length + girth
- — in
Girth = 2 × (width + height), using the two smaller dimensions.
Where the surcharges start
Published 2026 thresholds. These change most years and vary by service and contract — treat them as a prompt to check, not as a quote.
| Carrier | Rule | Threshold |
|---|---|---|
| UPS | Additional Handling (size) | Length + girth over 105 in, longest side over 48 in, or cubic volume over 10,368 in³ |
| UPS | Large Package Surcharge | Length + girth over 130 in, longest side over 96 in, cubic volume over 17,280 in³, or actual weight over 110 lb |
| UPS | Maximum accepted | Length + girth 165 in |
| FedEx | Oversize charge | Length + girth over 130 in, cubic volume over 17,280 in³, or actual weight over 110 lb |
| USPS | Oversized surcharge | Length over 108 in |
| USPS | Maximum accepted | Length + girth 130 in, 70 lb |
How it works
How dimensional weight is calculated
Carriers sell trailer and aircraft space, not just lifting capacity. A large box full of packing foam takes the room of a heavy one while earning far less, so carriers convert volume into a weight and bill on whichever figure is higher. That converted figure is the dimensional weight.
- Round each dimension up to the next whole inch. A 12.2-inch side is billed as 13.
- Multiply length by width by height to get cubic inches.
- Divide by the carrier’s DIM divisor.
- Round the result up to the next whole pound. That is the dimensional weight.
- Compare it with the actual weight. The greater of the two is the billable weight.
Two rules that catch people out
Fractions always round up, per dimension. FedEx began rounding every fractional inch up to the next whole inch on 18 August 2025 and UPS matched; USPS adopted the same rule on 12 July 2026. This is not rounding to the nearest inch — 8.01 inches becomes 9. Three dimensions rounding up together can add a surprising amount of billable volume, which is why a box measured at 12.1 × 10.2 × 8.1 is rated as 13 × 11 × 9.
USPS applies dimensional weight only above one cubic foot. From 12 July 2026 the USPS divisor dropped from 166 to 139 for Priority Mail Express, Priority Mail, Ground Advantage and Parcel Select — but only for packages larger than 1,728 cubic inches. At or below that, USPS bills the actual weight however light the package is. Most calculators apply the divisor to everything and over-report small boxes as a result. Note that because the round-up happens first, rounding alone can push a package over the threshold.
Choosing the right divisor
A lower divisor produces a higher dimensional weight, so the divisor on your account matters more than almost any other number in parcel pricing. UPS, FedEx and USPS all publish 139 for US domestic parcels. UPS walk-in retail counter shipments use 166, and negotiated contracts frequently specify 166 or better — if yours does, enter it as a custom divisor above.
| Divisor | Where it applies | Effect |
|---|---|---|
| 139 | UPS Daily Rates, FedEx Express and Ground, USPS above one cubic foot | The current published default |
| 166 | UPS retail counter, and many negotiated contracts | About 19 % lower dimensional weight |
| Custom | Whatever your carrier agreement specifies | Check your rate sheet |
Shipping pallets instead of parcels?
Dimensional weight is a parcel concept. LTL carriers solve the same problem — pricing bulky, light freight fairly — with classification rather than a divisor. If your freight moves on a pallet, use the freight class calculator instead.
Divisors, thresholds and surcharges change most years and vary by carrier, service level and negotiated account. Confirm the current figures with your carrier before you rely on them.
FAQ
Dimensional weight questions
What is dimensional weight?
How is dimensional weight calculated?
What is a DIM divisor?
What is billable weight?
Does dimensional weight apply to every USPS package?
How do I reduce dimensional weight charges?
Moving pallets, not parcels?
Get the density and NMFC freight class for an LTL shipment, on the density scale as it stands after the 2025 restructuring.