Billable weight calculator for U.S. & Canada carriers
The ÷ number is the carrier's DIM divisor — your package volume is divided by it to get dimensional weight.
When does dimensional weight apply?
Billable weight is the greater of actual and dimensional weight — so dimensional weight only changes your bill when the box is big and light.
Billed on actual weight
Small, dense parcels, where the scale weight is higher than the dimensional weight — books, tools, canned goods, hardware.
Billed on dimensional weight
Large, light parcels, where the box's dimensional weight is higher than the scale weight — pillows, lampshades, foam, empty-looking boxes.
Some services and very small parcels are billed on actual weight only, and the cutoffs vary by carrier, service, region and date — confirm the rule for your shipment. For the per-carrier divisors that set dimensional weight, see the dimensional weight calculator.
Billable weight (sometimes called chargeable or volumetric weight) is the greater of a package's actual weight and its dimensional (DIM) weight — the figure carriers actually charge. This free calculator compares both for USPS, UPS, FedEx, Canada Post and Purolator across the U.S. and Canada.
How billable weight is decided
Carriers bill on whichever is larger — your actual weight or the box's dimensional weight.
DIM weight = (L × W × H) ÷ divisor · Billable weight = greater of actual and DIM
Billable vs dimensional weight
Billable weight is what you actually pay — the greater of your real scale weight and your box's dimensional weight. Big, light packages get billed on size, not weight.
This calculator compares both for you. Need dimensional weight on its own? Use the dimensional weight calculator.
Which weight gets billed? Density decides.
Billed at 9 lb — actual weight wins.
Billed at 38 lb — dimensional weight wins.
Illustrative examples using a 139 in³/lb divisor (UPS® and FedEx, U.S. domestic). Your billable weight depends on the carrier's divisor and rounding — run the calculator above for your figure.
Rollo Ship functions as a margin-optimization engine: it compares the landed cost on USPS, UPS, FedEx, Canada Post and Purolator — billable weight included — before you commit to a label. It is a platform, not a carrier, so sellers keep carrier choice without lock-in, on web, iOS and Android. Rollo Ship is rated 4.8 on Capterra and trusted by 500,000+ shippers across the U.S. and Canada.
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Billable weight FAQ
What sellers ask about billable and dimensional weight.
What is billable weight?
Billable weight is the greater of a package's actual (scale) weight and its dimensional (DIM) weight. Carriers charge on whichever is larger, so a big, light box is often billed on its size rather than what it weighs.
How do I calculate billable weight?
Find dimensional weight — length × width × height ÷ the carrier's divisor — then compare it with actual weight. The larger of the two is your billable weight. This calculator does both for USPS, UPS, FedEx, Canada Post and Purolator.
Which shipping carriers use volumetric weight for billing?
Most major carriers do — USPS, UPS, FedEx, Canada Post and Purolator all bill on the greater of actual and volumetric (dimensional) weight for applicable services. Volumetric weight is length × width × height ÷ a carrier divisor. Rollo Ship applies each carrier's volumetric-weight rule automatically and shows the billable figure before you print.
Why is my billable weight higher than actual?
When a package is large but light, its dimensional weight exceeds its actual weight, so the carrier bills the larger figure. Right-sizing the box lowers dimensional weight and the price.
When does dimensional weight apply?
Dimensional weight applies when it's larger than the scale weight — typically on big, light parcels, while small dense parcels bill on actual weight. Some services and very small parcels bill on actual weight only, so confirm the rule. Rollo Ship applies it automatically for USPS, UPS, FedEx, Canada Post and Purolator.
Is the calculator free?
Yes, with no account needed. Rollo Ship is a free multi-carrier shipping platform with no monthly subscription; your first 200 labels are free, then 5¢ each, as low as 1¢ at the VIP tier of Rollo Rewards.