Frequently Asked Questions

Clear answers about units, divisors, billable weight, estimates, and privacy for the ShipCalc calculator.

Last updated: 2026-10-15

Prefer the interactive version? The same topics appear in the FAQ accordion on the homepage. For deeper explanations, visit the Guides.

What units can I use for calculations?

ShipCalc supports metric units (centimetres and kilograms) and imperial units (inches and pounds). You can switch systems at any time. When all values are filled, ShipCalc converts your inputs and recalculates results so unit systems are not mixed incorrectly.

How do I know the right dimensional divisor?

Dimensional divisors vary by carrier, service, and sometimes destination. Common starting points are 5000 for metric (cm³/kg) and 139 for imperial (in³/lb). Always confirm the divisor in your carrier’s current shipping guide or account settings before you charge a customer or buy a label.

What is the difference between actual weight and dimensional weight?

Actual weight is what a scale measures. Dimensional weight estimates how much space a parcel occupies relative to its size: volume divided by the dimensional divisor. Carriers often bill the higher of the two, which ShipCalc shows as estimated billable weight.

Why is my billable weight higher than my actual weight?

If dimensional weight exceeds actual weight, carriers typically bill the higher value. Lightweight but bulky packages commonly trigger this. Improving packaging efficiency or choosing a denser pack can reduce dimensional weight in some cases.

Can I include multiple additional charges?

Yes. Enter the combined total of fuel, residential, remote-area, Saturday delivery, or other surcharges in the Additional charges field. ShipCalc adds that amount to your base shipping charge when estimating total cost.

Does ShipCalc provide official carrier quotes?

No. Cost results are estimates based only on rates and fees you enter. They are not live carrier tariffs, negotiated account rates, or bookable quotes. Always verify final charges with your carrier or shipping platform before shipping.

Are carrier rounding rules the same everywhere?

No. Carriers may round dimensions up, apply minimum billable weights, or use service-specific increments. ShipCalc uses a transparent general calculation profile for education and estimation, not carrier-specific rating engines.

Is my shipment data sent to a server?

Calculator inputs are processed in your browser for this version of ShipCalc. We do not operate a backend that stores your package dimensions or rates for the core calculator. See the Privacy Policy for details about theme preferences, hosting logs, and any future advertising or analytics tools.

Can I use ShipCalc for commercial shipping decisions?

You may use ShipCalc as a planning aid. It is not a substitute for carrier rating tools, shipping software, or professional logistics advice. You remain responsible for confirming dimensions, rates, taxes, duties, and service eligibility.