About HandyNumbers

HandyNumbers is a growing collection of free calculators for everyday decisions. The goal is simple: put the useful number first, explain how it was calculated, and avoid unnecessary sign-ups or clutter.

How we build calculators

Each calculator is designed around a specific task, uses clearly labelled inputs and shows the formula or assumptions behind the estimate. Calculations run in your browser.

Accuracy and limitations

We aim to make the maths clear and useful, but real-world costs and outcomes can differ because of fees, tax rules, tariffs, lender terms, product specifications and individual circumstances. HandyNumbers is a planning tool, not professional advice.

Suggest a tool or correction

Email hello@handynumbers.com.