Question
Why can a light package still be expensive to ship?
Because large boxes take up carrier space even when they are not heavy, so dimensional-weight pricing can push the billed weight above the actual scale weight.
Ecommerce
Use OmniCalc's dimensional weight calculator to estimate carrier-billed weight from package size and actual scale weight.
Dimensional weight calculator
Use this to compare dimensional weight against actual weight so you can spot when package size, not scale weight, is driving shipping charges.
Formula: length × width × height ÷ divisor. Carriers often bill the higher of actual weight and dimensional weight.
Why this result matters
An ecommerce shipping calculator that compares dimensional weight with actual weight so operators can estimate which number carriers are likely to bill. Use the tool above to enter a few clear inputs and get a practical answer you can use right away.
This dimensional weight calculator helps ecommerce operators and shippers estimate when package size will push billed shipping weight above the actual scale weight. It is useful because many carriers charge whichever is higher: dimensional weight or actual weight.
Formula and method
The calculator multiplies package length, width, and height to get volume, divides the result by a dimensional-weight divisor, and compares that number against actual weight. The higher value becomes the estimated billable weight.
Example
If a package measures 20 × 16 × 12 inches with an actual weight of 18 pounds, the calculator estimates dimensional weight using the standard parcel divisor and shows whether the carrier is likely to bill by dimensional weight or actual weight.
FAQ
Short answers to the questions people often ask before or after using the tool.
Question
Because large boxes take up carrier space even when they are not heavy, so dimensional-weight pricing can push the billed weight above the actual scale weight.
Question
It is the higher of actual weight and dimensional weight, which is commonly the number carriers use for pricing.
Question
No. Divisors can vary by carrier and service, but common defaults are 139 for inches/pounds and 5000 for centimeters/kilograms.
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