Dimensional Weight Calculator

Enter your package dimensions and actual weight to see its dimensional (DIM) weight and the billed weight your carrier will actually charge on. The divisor is editable, so you can match any carrier's current rules. Everything runs in your browser — nothing is uploaded.

📖 How it works & FAQ

Length (in)

Width (in)

Height (in)

Actual weight (lb)

Divisor preset

DIM divisor (editable)

Estimate only. Carriers round weights up and may apply minimums, surcharges, or different divisors by service — check current carrier rules before pricing shipping.

Why dimensional weight matters

Major carriers such as UPS, FedEx and USPS do not just weigh your box — they measure it. A light but bulky package takes up truck space, so carriers charge for volume using dimensional (DIM) weight: length × width × height in inches, divided by a divisor (139 is the common domestic default; 166 shows up in retail and some international rates). Your billed weight is whichever is greater — the actual scale weight or the DIM weight — rounded up to the next whole pound. For sellers shipping pillows, framed prints, or mugs in generously padded boxes, DIM weight is the silent reason a label costs more than the scale suggests. The divisor figures here are approximate defaults you can edit; check the carrier’s current fees before relying on any number — these are estimates only, not financial advice.

How to use it

Measure the outer dimensions of the packed box in inches and enter length, width and height.
Enter the actual weight in pounds, with all packaging included.
Pick a divisor preset or type your own — carriers change these values, so the field stays editable.
Read the live results: raw DIM weight, actual weight, and the billed weight your rate will be based on, with a note on which one governs.

If DIM weight governs, the fastest savings usually come from a smaller box. Even shaving an inch off one side can drop the billable pound bracket, because volume grows multiplicatively.

FAQ

Which divisor should I use?: 139 is the usual starting point for UPS and FedEx domestic rates. 166 appears in some retail and international rate charts. Negotiated commercial accounts sometimes get a higher (better) divisor — enter whatever your agreement says.
Why does the billed weight round up?: Carriers bill in whole-pound increments, so both actual and DIM weight are rounded up before comparison. A 4.1 lb package bills as 5 lb.
Does USPS always apply DIM weight?: USPS generally applies dimensional pricing only to larger parcels — typically over one cubic foot (1,728 cubic inches). Smaller packages are billed on actual weight for most services.
Do I measure the product or the box?: Always the outer shipping box, at its longest point on each side, including any bulge. Carriers measure the box, not what is inside it.