Don's Tools · Calculators

Calculators

Loans, percentages, dates, compound interest and a group bill splitter, all in your browser.

Calculators is a set of free tools on Don's Tools including percentage, loan and EMI, age, BMI, date difference and compound interest calculators, a combined countdown and stopwatch, and a Splitwise-style bill splitter, all running in your browser with nothing uploaded.
Percentage Calculator›Loan & EMI Calculator›Age Calculator›BMI Calculator›Date Difference›Compound Interest›Countdown & Stopwatch›Bill Splitter›Discount Calculator›

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Frequently asked questions

Are these calculators free and private?

Yes. They are free, need no sign-up, and run entirely in your browser, so anything you enter stays on your device.

Are the financial results exact?

They are careful estimates using standard formulas, useful for planning. For decisions that matter, confirm with your bank or a professional.

Does the bill splitter save my data?

Yes, in your browser, and you can keep multiple splits and back them up as JSON.

Do I need to install anything?

No, everything works in a modern browser on any device.