Frequently asked questions
Are these calculators free?
Yes. Every calculator is free to use, with no account or sign-up.
Is the information I enter stored or sent anywhere?
No. Calculations run in your browser. If you choose to copy a share link, your values are placed in that link, and only people you send it to can see them.
How accurate are the results?
Calculators use standard formulas, which are shown on each page along with a worked example, and are tested against known results. They give estimates for information only, and real-world products can differ because of fees, taxes and rounding rules.
Can I use the calculators on my phone?
Yes. The site is built for small screens first, with large inputs and tables that reflow to fit narrow displays.
How can I report a mistake or suggest a calculator?
Use the details on the contact page. Please include the calculator name, the values you entered and the result you expected.