Dimensional weight calculator
Carriers charge for the space a box takes up, not only its weight. Drag the box to your carton's size, or type it, to see what UPS, FedEx, USPS and DHL bill it as. Paste a list of SKUs to check every box at once.
Carriers charge for the space a box takes up, not only what it weighs. Dimensional weight turns that space into pounds, and you pay whichever is higher.
Drag the green corners to resize the box. Inside the dashed cube, USPS bills actual weight.
Billable weight at UPS and FedExThe weight you pay for: the larger of what the box weighs and its dimensional weight, rounded up to the next pound.
19 lb
The box weighs 6 lb but takes up the space of 19 lb, so carriers bill 19 lb, 3.2× its weight. One inch off the width brings it to 17 lb.
- UPS, FedEx, USPS, DHL Express19 lb
6 lb of product, plus 13 lb of space you pay for.
- Dimensional weightThe box's size turned into weight: length × width × height ÷ the divisor. Carriers use it so a big, light box pays for the space it takes on the truck.
- 19 lb
- Dim divisorThe number carriers divide a box's volume by. A bigger divisor means a lower dimensional weight. UPS, FedEx, USPS and DHL use 139 at daily rates; UPS retail counters use 166.
- 139 in³ per lb
Rounded the way carriers do: each side to the nearest whole inch (USPS rounds up), the weight up to the next pound.
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Many SKUs? Check every box at once
Paste one SKU per line as sku, length, width, height, weight in inches and pounds, or drop a CSV export. It runs in your browser; nothing is uploaded.
How to read your number
Dimensional weight is the weight a carrier charges for the space a package takes up: length × width × height divided by the carrier's divisor. An 18 × 14 × 10 inch box is 2,520 cubic inches; ÷ 139 that's 18.1, billed as 19 lb at UPS, FedEx, USPS and DHL, even though it weighs 6 lb. Carriers charge the larger of the actual and dimensional weight, the billable weight.
Why it matters
Light, bulky orders are where shipping quietly eats margin. The 6 lb box above is billed as 19 lb, more than three times its weight. Cutting it to 16 × 12 × 10 inches brings it to 14 lb, five fewer billed pounds on every order that ships in it. Getting it to 12 × 12 × 12 or smaller lets USPS bill the actual 6 lb.
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Formula
Dimensional weight = length × width × height ÷ divisor; billable weight = the larger of actual and dimensional weight
In inches and pounds the divisor is 139 at UPS, FedEx, USPS and DHL Express; USPS applies it only to packages over one cubic foot. In centimeters and kilograms it's 5,000. Carriers round each side to a whole inch (USPS rounds up) and the result up to the next whole pound, or half kilogram.
Other ways to calculate dimensional weight
- UPS, FedEx and DHL, inches
- Dim weight (lb) = L × W × H (in) ÷ 139
- Ground and air parcels at daily or account rates, on every package size.
- USPS, inches
- Dim weight (lb) = L × W × H (in) ÷ 139, over 1,728 in³ only
- Priority Mail, Priority Mail Express and Ground Advantage packages over one cubic foot. Smaller ones bill on actual weight.
- UPS retail
- Dim weight (lb) = L × W × H (in) ÷ 166
- Packages paid at retail rates, such as at a UPS Store counter.
- Metric, centimeters
- Dim weight (kg) = L × W × H (cm) ÷ 5,000
- International express with UPS, FedEx and DHL, and most carriers outside the US.
- Air cargo, centimeters
- Volumetric weight (kg) = L × W × H (cm) ÷ 6,000
- Air freight booked through a forwarder rather than a parcel carrier. See the CBM calculator.
What is dimensional weight?
Dimensional weight, also called DIM weight or volumetric weight, is a pricing rule that charges a package by its size when it's light for its size. A truck or plane fills up by space before it fills up by weight, so carriers price the space.
Every package gets two weights: the actual weight on a scale and the dimensional weight from its size. The carrier bills whichever is higher, the billable weight, and looks up the rate for that weight and zone.
How to calculate dimensional weight
- Measure the box at its longest, widest and tallest points, bulges included: 18 × 14 × 10 inches.
- Round each side to the nearest whole inch.
- Multiply: 18 × 14 × 10 = 2,520 cubic inches.
- Divide by the divisor: 2,520 ÷ 139 = 18.13 lb.
- Round up to the next pound: 19 lb.
- Compare with the actual weight, rounded up too, and bill the larger: 19 lb against a 6 lb box.
Check dimensional weight for every SKU at once
- Download the template above, or export your products with their box sizes and weights.
- Paste the rows or drop the CSV: one SKU per line as sku, length, width, height, weight.
- Read the table: each SKU's billable weight at UPS, FedEx and DHL and at USPS, with the ones billed on size highlighted.
- Download the results and use the billable weight, not the scale weight, in your shipping rates.
How to calculate dimensional weight: a worked example
A candle brand ships a gift set in an 18 × 14 × 10 inch box that weighs 6 lb packed.
- Volume = 18 × 14 × 10 = 2,520 cubic inches (1.46 cubic feet)
- UPS, FedEx and DHL: 2,520 ÷ 139 = 18.13, billed as 19 lb
- USPS: over one cubic foot, so the same 2,520 ÷ 139, billed as 19 lb
- Actual weight 6 lb is lower at every carrier, so dimensional weight sets the price
The 6 lb box bills as 19 lb everywhere. A 16 × 12 × 10 inch box would bill as 14 lb, and a 12 × 12 × 12 box as 6 lb at USPS.
How to lower your dimensional weight
Right-size the box. Every inch counts three ways, since it multiplies the other two sides. Keep two or three box sizes that fit your best sellers snugly instead of one large box for everything.
Use mailers for soft goods. Poly mailers and padded envelopes have little volume, so apparel and small accessories often bill on actual weight.
Stay at or under one cubic foot at USPS. Packages of 1,728 cubic inches or less bill on actual weight there, so a light 12 × 12 × 12 box can cost much less than a 13 × 12 × 12 one.
Price shipping on the billable weight. If you charge shipping by actual weight, bulky orders lose money. Use billable weight in your shipping rates and contribution margin.
| Box (inches) | Cubic feet | UPS, FedEx, DHL | USPS |
|---|---|---|---|
| 6 × 6 × 6 | 0.13 | 2 lb | Actual weight |
| 10 × 8 × 6 | 0.28 | 4 lb | Actual weight |
| 14 × 10 × 8 | 0.65 | 9 lb | Actual weight |
| 12 × 12 × 12 | 1.00 | 13 lb | Actual weight |
| 16 × 12 × 10 | 1.11 | 14 lb | 14 lb |
| 18 × 14 × 10 | 1.46 | 19 lb | 19 lb |
| 24 × 18 × 12 | 3.00 | 38 lb | 38 lb |
| 20 × 20 × 20 | 4.63 | 58 lb | 58 lb |
Questions about dimensional weight
- What is dimensional weight?
- Dimensional weight is the weight a carrier charges for a package's size: length × width × height ÷ a divisor, 139 in inches at UPS, FedEx, USPS and DHL. You pay the larger of it and the actual weight. Outside the US and in air freight it's called volumetric weight, usually centimeters ÷ 5,000 for express parcels or ÷ 6,000 for air cargo.
- How do you calculate dimensional weight?
- Multiply length, width and height in inches, then divide by the carrier's divisor: 139 at UPS, FedEx, DHL Express and USPS. Round up to the next pound. An 18 × 14 × 10 box is 2,520 ÷ 139 = 19 lb at UPS. In centimeters, divide by 5,000 for kilograms.
- What is the dimensional weight divisor for UPS and FedEx?
- 139 cubic inches per pound for both, on domestic and international shipments, and 5,000 cubic centimeters per kilogram in metric. A negotiated contract can set a higher divisor, which lowers dimensional weight, so check your account's agreement.
- Does USPS charge dimensional weight?
- Yes, for packages larger than one cubic foot (1,728 cubic inches) on Priority Mail, Priority Mail Express and Ground Advantage. USPS now divides by 139, the same as UPS and FedEx; older guides say 166. Packages of one cubic foot or less are priced on actual weight.
- What is billable weight?
- The weight a carrier charges you for: the larger of the package's actual weight and its dimensional weight, both rounded up. A 6 lb box with a 19 lb dimensional weight bills as 19 lb.
Sources
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