Contact

Get in touch

Questions about a calculator, a formula or something on a page? Email us and include the page URL plus the inputs you used so we can reproduce what you saw.

What to send

Good things to report: a result that looks wrong, an input that should be accepted but is rejected, a formula you think is stated incorrectly, or a broken link.

Please do not send personal data you do not need to share — calculations run locally in your browser and we never see your inputs unless you choose to describe them.