We aim to reply within a few business days. There is no phone line and no live chat, so email is the only route.
Found a calculation error?
These are the messages we most want to receive, and they get looked at first. To make a fix quick, include as much of the following as you can.
- Which calculator, and the URL of the page.
- The exact values you entered, including the units you selected.
- The result you got, and the result you expected.
- Your working, if you have it. It usually pinpoints the disagreement immediately.
Requesting a tool or an input
Tell us what decision you are trying to make rather than the interface you imagine. Knowing that you need to quote wholesale orders with tiered pricing is far more useful than a request for another number field, and it often turns out the gap is in an existing tool rather than a missing one.
Privacy requests
For questions about data, cookies, or advertising, or to make a request under privacy law, email the same address and mention privacy in the subject line so it is routed correctly. The privacy policy explains what is and is not collected.
What we cannot help with
We are not able to give professional advice on your specific situation. That includes pricing consultancy, accounting, tax, legal, or financial guidance, and reviewing your business figures. For those, please speak to a qualified professional in your jurisdiction.
Advertising and partnerships
We do not accept paid guest posts, sponsored links, or link exchanges, and requests of that kind are not answered. Advertising on the site is handled through ad networks rather than direct arrangements.