About & methods

About ParcelMath

ParcelMath is an independent, free utility focused on one task: dimensional weight calculator. It presents the formula and assumptions alongside the answer so that a result can be checked rather than taken on trust.

What it does

Compare scale weight with dimensional weight using your chosen divisor. Test box sizes and optional weight rounding before checking a carrier quote.

How calculations work

Volume = length × width × height Dimensional weight = volume ÷ divisor Governing weight = max(actual, dimensional) Optional: round upward to chosen weight increment Total = rounded weight × identical parcel count

Calculations run on your device. Displayed quantities are rounded to at most two decimal places; whole-pack purchasing counts round upward. More precision is retained internally. Display rounding is not a guarantee about a supplier or device measurement tolerance.

What it does not establish

Not a carrier quote. Dimensions are used as entered. Carrier dimension rounding, minimums, special handling and surcharges are not included.

The guides are original worked explanations of arithmetic and practical input choices. They are not reports of physical tests, endorsements by a provider, or professional assessments. Verify important purchasing assumptions with the relevant supplier.

Reproduce a result

Keep the selected units, every input, the formula and the downloaded text summary together. If a result differs from a provider quote, check the assumptions before comparing prices. A wrong divisor, pack coverage or resolution target can give mathematically consistent but unsuitable estimates.

Method and guides reviewed November 8, 2026.