Who builds it

ShippingMath is built and maintained by Harsh Parmar, an independent developer. I started it after seeing how often small online sellers lose margin to dimensional weight without noticing, and how few calculators explain why a package was billed the way it was.

Why it exists

Many calculators stop at a formula. ShippingMath keeps scale weight, dimensional weight, billable weight, package volume and margin together so a seller can decide whether to change the carton, the price or the shipping charge.

How the rules are checked

Carrier rules change. Each preset is checked against the carriers' published rules, and the methodology page lists the sources and the date of the last review. If you spot a rule that has changed, please tell us.

What it is not

ShippingMath is independent planning software. It is not affiliated with any carrier, and it is not a postage quote, an accounting system or a substitute for your current carrier agreement.

Free first

The tools are free and do not require registration. Paid features will only be considered if users repeatedly need saved catalogues, larger workflows, integrations or team reporting.