About Us
Tools builds free calculators and tools that explain themselves. We started it because too many calculator sites give you a number with no way to tell whether it is right.
What we do
We make calculators for the questions people actually search for: what a loan will cost, what a salary means after tax, how many calories to eat, when a baby is due, how long ago a date was. Each tool is paired with a guide that explains the method, shows a worked example and links to the official source behind every figure.
How we build every tool
- Start from the source. We use the formula or rule an expert would use, such as the amortisation formula for loans, HMRC and IRS tables for tax, and the Mifflin–St Jeor equation for calories.
- Test against known answers. Before publishing, results are checked against worked examples from the source and against independent calculations.
- Show the working. Every page explains the method, states its assumptions and lists its sources.
- Keep it current. Tools that depend on rates or thresholds show the tax year they apply to and are reviewed when those figures change.
You can read more in our editorial policy.
Who is behind Tools
Tools is edited by our editorial team (editor).
See the editor’s page for background and the topics we cover.
Our promises
- Free to use. The site is funded by advertising. Ads never change a result or a recommendation.
- Private. Calculations run in your browser. We do not ask for sign-ups and we do not store what you type into a tool.
- Honest about limits. A calculator is a starting point. Where a decision needs a professional, such as a doctor, a midwife or a regulated financial adviser, we say so.
Get in touch
Spotted a mistake, or want a tool we do not have yet? Email maservices131@gmail.com or use the contact page. We read every message.