Contact

Reporting a calculation error

This is the most valuable thing you can send, and the easiest for us to act on. Please include:

• The tool you used
• Every input value
• What the tool returned
• What you expected, and how you worked it out

We treat these as bugs and fix them. If a rate table or regional constant has gone out of date, that is exactly the kind of thing we want to hear about.

Requesting a tool

We add tools where the demand is real and the calculation is well defined. Useful requests tell us the question you were trying to answer rather than just naming a tool, because the same need often has a simpler implementation than the name suggests.

We are especially interested in anything that would otherwise require you to upload a document, a payslip, or an identity document to a stranger's server in order to get an answer.

Advertising and business enquiries

For direct advertising enquiries, please include the publication you are asking about and the country your audience is primarily in. Note that OmniTools is funded by Google AdSense, and we do not sell or broker individual placements.

Privacy questions

We receive no tool inputs, no account data, and no personal information, because we have no mechanism to collect any of it. If your question is about advertising cookies, that is a matter for Google — see the privacy policy for the relevant settings.

What we cannot help with

We do not give financial, legal, tax, or medical advice, and we cannot review your specific circumstances. Our calculators check arithmetic; they do not make decisions.