Dimensional Weight Calculator
See what UPS, FedEx or USPS will bill your package at, and how many pounds a right-sized box saves on every order.
Your package
1Your current box Outside size of the box you ship
2Carrier
3Compare with a perfect-fit box Optional
What Is Dimensional Weight?
Carriers do not only charge by how heavy a package is. They also charge for the space it takes up in the truck. Dimensional weight (DIM weight) turns the size of your box into a weight. If the DIM weight is higher than the actual weight, that is what you pay for. This is why a light product in a big box can cost as much to ship as a heavy one.
How Dimensional Weight Is Calculated
- Measure the outside of the box in inches and round each side to the nearest whole inch.
- Multiply length x width x height to get the volume in cubic inches.
- Divide by the carrier's DIM divisor and round up to the next pound.
- Compare it with the actual weight, rounded up to the next pound. The higher number is your billable weight.
Example: a 12 x 10 x 6 inch box has a volume of 720 cubic inches. With a divisor of 139, that is 5.18, which rounds up to 6 lb. If the package only weighs 2 lb, you are still billed for 6 lb.
Common DIM Divisors
| Carrier | Common divisor | Note |
|---|---|---|
| UPS | 139 | Your account may use a different divisor |
| FedEx | 139 | Your account may use a different divisor |
| USPS | 166 | Commonly applied to packages over 1 cubic foot (1,728 cubic inches) |
Divisors can change, so always confirm with your carrier and use the Custom option above if yours is different.
How to Lower Your Shipping Weight
- Right-size the box. Every inch of empty space is paid for on every order. Use our box size calculator to find the size your product actually needs.
- Choose the right style. Mailer boxes built to your product size ship with far less wasted space than a stock carton.
- Cut the filler. If you need lots of void fill, the box is probably too big.
Frequently Asked Questions
What is dimensional weight?
Dimensional weight (DIM weight) is a pricing method carriers use for large, light packages. They multiply the length, width and height of the box and divide it by a number called the DIM divisor. If that result is higher than the actual weight, you pay for the dimensional weight.
How do I calculate dimensional weight?
Measure the box in inches and round each side to the nearest whole inch. Multiply length x width x height, divide by your carrier's DIM divisor and round up to the next pound. Your billable weight is the higher of this number and the actual weight.
What DIM divisor do UPS, FedEx and USPS use?
A divisor of 139 is common for UPS and FedEx, and USPS commonly uses 166 for packages larger than one cubic foot. Divisors can change and some business accounts have their own, so check your carrier account and enter your own divisor if it is different.
How can I lower my dimensional weight?
Use a box that fits your product closely. Removing even an inch of empty space on each side can drop the billable weight by pounds on every package. A custom mailer built to your product size is one of the easiest ways to do this.
Does this calculator show shipping prices?
No. Shipping rates depend on your carrier, service, zone and account, so this tool shows weight in pounds, not dollars. Use the billable weight with your own carrier rates to see the cost.
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