About NumberUtils

What NumberUtils is

NumberUtils is a growing collection of free everyday math calculators — currently 20, starting with percentages, ratios and averages. Every calculation runs in your browser: nothing you enter is sent anywhere.

Accuracy

• Every calculator is backed by a typed, independently-tested calculation module — the page never hand-types a number the engine did not compute.
• Results are rounded only to remove floating-point noise, never to hide precision.
• Where a calculation has more than one accepted convention (for example, percentage change versus percentage difference), the page states which one it uses.

Independence and limits

NumberUtils is an independent website. It does not provide financial, tax, legal or other professional advice, and its results are not certified for any official purpose. See the terms of use.

Feedback

If a result looks wrong, please get in touch. A confirmed calculation error is treated as a bug and gets a regression test.