About Clear Money Math

Clear Money Math builds free, fast calculators for the money decisions people actually face: when you can stop saving for retirement, which debt to pay off first, whether a mortgage recast is worth it.

How we build our calculators

• The math is on the page. Every calculator explains its formula and walks through a worked example, so you can check the result yourself.
• Tested against known values. Each calculation is covered by automated tests against textbook results (for example, standard loan amortization tables) before it's published.
• Reviewed and dated. Each page shows when it was last reviewed. If you spot an error, tell us and we'll fix it.
• Private by design. Calculations run entirely in your browser. The numbers you type are never sent to our servers.

What we are not

We're not financial advisers, and nothing on this site is personal financial, tax or legal advice. Our tools give estimates based on the assumptions you enter. For decisions with large consequences, consider speaking with a qualified, fee-only professional.

How the site is funded

Clear Money Math is free to use and supported by advertising. Ads never influence how a calculator works or what it shows.

Questions or corrections: hello@clearmoneymath.com