Dimensional Weight Calculator
Carriers bill you for the space a box takes up, not just what it weighs. Enter your dimensions below to see the billable weight UPS, FedEx, USPS and DHL will actually charge you for, and whether you’re about to be hit by a surcharge.
Your package
Measure the outside of the box at its widest points.
Or start from a common size
Volume: 3,024 cu in (1.75 cu ft)
| Carrier | Divisor | DIM weight | You’re billed for |
|---|---|---|---|
| UPSDaily Rates | 139 | 22 lbs | 22 lbsDIM |
| UPSRetail Rates | 166 | 19 lbs | 19 lbsDIM |
| FedExExpress & Ground | 139 | 22 lbs | 22 lbsDIM |
| USPSPriority Mail & Ground Advantage | 166 | 19 lbs | 19 lbsDIM |
| DHL ExpressU.S. domestic | 139 | 22 lbs | 22 lbsDIM |
Billable weight is the greater of actual and dimensional weight. Dimensions are rounded to the nearest whole inch and the result up to the next whole pound, the way carriers do it.
How dimensional weight works
Every parcel carrier charges on billable weight, which is the greater of your package’s actual weight and its dimensional weight. Dimensional weight is a stand-in for volume: trucks and aircraft run out of space long before they run out of weight capacity, so carriers price the cubic space you consume.
The formula
(Length × Width × Height) ÷ DIM divisor = dimensional weight
Round each dimension to the nearest whole inch before multiplying, then round the result up to the next whole pound. A lower divisor means a higher dimensional weight, which is why the shift from 166 to 139 raised costs across the industry.
Where it hurts most
Dimensional weight punishes anything light and bulky: pillows, pet beds, apparel in rigid cartons, subscription boxes with generous void fill, and anything shipped in a box that was chosen for convenience rather than fit. A 24″ × 20″ × 18″ carton weighing 9 lbs has a dimensional weight of 63 lbs at a 139 divisor. You would pay roughly seven times the weight you actually shipped.
Four ways to bring it down
Right-size your cartons. Cutting one inch from each side of a common box often removes a full pound of billable weight from every single order.
Replace rigid boxes with poly mailers wherever the product allows. Soft goods are the easiest win.
Reduce void fill instead of compensating for an oversized box. The filler is a symptom, not the fix.
Audit your carton mix quarterly. Most brands accumulate box sizes over time and never retire the ones that no longer fit anything.
For a deeper walkthrough of how DIM pricing evolved and what it means for your margins, read Understanding Dimensional Weight Pricing. To model your full per-order fulfillment cost, covering pick, pack, storage and shipping together, use our fulfillment cost calculator.
Dimensional weight FAQ
What is dimensional weight?
Dimensional (DIM) weight is a pricing method that charges you for the space a package occupies rather than how much it weighs. Carriers multiply length by width by height, then divide by a fixed number called the DIM divisor. You are billed on whichever is greater: actual weight or dimensional weight.
How do I calculate dimensional weight?
Multiply length by width by height in inches to get cubic inches, then divide by the carrier’s DIM divisor: 139 for UPS Daily Rates, FedEx and DHL, or 166 for UPS Retail and USPS. Round each dimension to the nearest whole inch first, and round the result up to the next whole pound.
What is the DIM divisor for UPS and FedEx in 2026?
UPS and FedEx both use a divisor of 139 for U.S. domestic shipments on daily rates. UPS Retail pricing uses 166. A lower divisor produces a higher dimensional weight, so 139 is the more expensive of the two.
Does USPS charge dimensional weight?
Yes, but only on packages larger than one cubic foot (1,728 cubic inches). Below that threshold USPS bills on actual weight alone. Above it, USPS applies a divisor of 166 to Priority Mail, Priority Mail Express and USPS Ground Advantage.
How do I reduce dimensional weight charges?
Use the smallest box that safely fits the product, cut void fill so cartons are not oversized, switch rigid boxes to poly mailers where the product allows, and review your carton mix regularly. Shaving one inch off each side of a common carton often removes a whole pound of billable weight on every order.
Which weight am I actually billed for?
The greater of the two. If your package weighs 8 lbs but its dimensional weight is 22 lbs, you pay the 22 lb rate. This is why lightweight, bulky products are disproportionately expensive to ship.
Paying for air?
Our WMS picks the smallest box each order safely fits, so you stop paying to ship empty space, and we ship on negotiated carrier rates. Send us your box dimensions and monthly volume and we’ll show you what the same shipments would cost through 3PL Center.