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.
Enter a length, width and height greater than zero.
When does dimensional weight apply?
Billable weight is the greater of actual and dimensional weight, so dimensional weight only changes your bill in two situations — and USPS has a size floor the other carriers don't.
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.
USPS only: above 1 ft³
USPS applies dimensional weight only to packages over 1,728 in³ on applicable services. A 10 × 10 × 10 in box is 1,000 in³, so it bills on actual weight. UPS and FedEx apply it at every size.
Thresholds, rounding and service exclusions are set by each carrier and change without notice — 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. It is the figure carriers actually charge. This free calculator compares both for USPS, UPS, FedEx, Canada Post and Purolator across the U.S. and Canada, applying each carrier's measurement rounding and the USPS one-cubic-foot threshold.
How billable weight is decided
Three steps. Carriers bill on whichever is larger, your actual weight or the box's dimensional weight.
Measure and round
Measure length, width and height and round each one to the nearest whole inch or centimetre. Carriers measure the same way, so rounding first is what makes your figure match the invoice.
Divide volume by the carrier divisor
Multiply the rounded dimensions for volume, then divide by the carrier's DIM divisor to get dimensional weight. USPS applies dimensional weight only to packages over one cubic foot.
Take the greater figure
Compare dimensional weight with the weight on your scale. The larger of the two is your billable weight, rounded up the way the carrier rounds.
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, size threshold and rounding — run the calculator above for your figure.
A weight is not a price
Billable weight is one input. What you pay also depends on carrier, service and zone. Rollo Ship prices the same package on USPS, UPS, FedEx, Canada Post and Purolator, at discounted rates, before you print.
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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 shippers keep carrier choice without lock-in, on web, iOS and Android. Rollo Ship is rated 4.8 on Capterra. More than 500,000 shippers across the U.S. and Canada use Rollo.
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Rollo Ship is the free multi-carrier shipping platform for shippers across the U.S. and Canada. It applies billable-weight rules for USPS, UPS, FedEx, Canada Post and Purolator, then shows the discounted rate on each before you print.
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Billable weight FAQ
What shippers 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?
Round each dimension to the nearest whole inch, multiply for volume, then divide by the carrier's divisor to get dimensional weight. Compare that with your scale weight and take the larger figure. This calculator does both for USPS, UPS, FedEx, Canada Post and Purolator.
Does USPS charge dimensional weight on small boxes?
No. USPS applies dimensional weight only to packages over one cubic foot, which is 1,728 cubic inches, on applicable services. A 10 x 10 x 10 in box is 1,000 cubic inches, so it is billed on actual weight. UPS and FedEx apply dimensional weight at every size.
Do carriers round my package dimensions?
Yes. Carriers round each dimension to the nearest whole inch or centimetre before working out volume, so 12.4 in is measured as 12 and 12.6 in as 13. This calculator rounds the same way, which is why its figure lines up with the invoice.
Which shipping carriers use volumetric weight for billing?
USPS, UPS, FedEx, Canada Post and Purolator all bill on the greater of actual and volumetric (dimensional) weight for applicable services. The thresholds differ: USPS applies it above one cubic foot, while UPS and FedEx apply it at every size. Rollo Ship applies each carrier's 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. The calculator shows the volume you would need to get under to be billed on actual weight instead.
What is length plus girth?
Length plus girth is the longest side plus twice the width and height added together. Carriers use it to flag oversize packages and additional-handling surcharges, separately from dimensional weight. The calculator shows the figure so you can check it against your carrier's limits.
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 cents each, as low as 1 cent at the VIP tier of Rollo Rewards.