Dimensional Weight Calculator
Find the billable weight UPS, FedEx, USPS or DHL will charge you.
Billable weight
5.18lb
Dimensional weight is higher — UPS will bill on 5.18 lb.
Divisors above are the published retail rates from each carrier’s documentation. Contract customers often have softer divisors — pick “Custom” and enter your own.
Carriers don’t just charge by weight — they charge by whichever is greater, the actual weight or the dimensional weight derived from the box size. A large, light parcel can cost as much as a small, heavy one. This page explains the formula, lists the published divisors, and shows where the savings actually come from.
The formula, in one line
Then: billable weight = max(actual, dim). The divisor encodes how aggressively the carrier penalises low-density shipments.
Published divisors, by carrier
Retail rate, domestic and international.
Retail rate, domestic and international.
Applied only on parcels > 1 cu ft.
International standard.
Five ways to ship lighter on the invoice
- 1Right-size your boxes
Volume is the only input you fully control. A smaller box drops dim weight one-for-one.
- 2Remove void fill where safe
Air weighs nothing — but dimensions do. Tighter packs ship cheaper.
- 3Use mailers for small flat items
Many DIM rules don’t apply or are looser for envelopes and mailers.
- 4Negotiate a softer divisor
Volume shippers can often pull divisors from 139 down to 166 or 194 in contract.
- 5Audit shipments quarterly
DIM creep is one of the most common hidden costs in shipping budgets.
When DIM doesn’t apply
Most domestic USPS services skip DIM for parcels under one cubic foot. Flat-rate options charge by category, not weight. Some freight services use density-based dim-factoring rather than per-package DIM. When the math gets close to the threshold, run a real carrier rate quote on the exact dimensions — this calculator gives you the formula, not a contract price.
Frequently asked
- What exactly is dimensional weight?
- A pricing weight derived from volume. Carriers charge on whichever is greater — actual weight or dimensional weight — so a light, bulky box doesn’t fill cargo space at a discount.
- How is it calculated?
- Multiply length × width × height in your chosen unit, then divide by the carrier’s divisor. For UPS, FedEx and DHL Express that’s 139 (in³/lb) or 5,000 (cm³/kg). USPS uses 166 / 6,000.
- Is dimensional weight the same as billable weight?
- No. Dimensional weight is one of the two candidates. Billable weight is whichever of actual weight or dimensional weight is greater — that is what you pay on.
- Why is my carrier charging more than the scale weight?
- Because dimensional weight came out higher. Your parcel is large relative to its actual weight, so the carrier is billing on its volume instead.
- Do the divisors ever change?
- Yes — carriers update them every year or two, and contract customers often have softer numbers in their rate cards. The figures here are the current published retail rates; always cross-check your own carrier agreement.