Free Calculators
Transparent calculators that show their working: percentages, loan and EMI with a full amortisation schedule, compound interest, age, date maths, BMI and unit conversion.
8 free calculators tools
- Percentage Calculator — Every percentage question, worked out
- Unit Converter — One value, every unit, all at once
- Loan Calculator — Payment, interest & full amortisation
- Compound Interest Calculator — Growth, contributions & real returns
- Age Calculator — Exact age, to the day and minute
- Date Calculator — Days between dates & business days
- BMI Calculator — BMI, BMR, TDEE & calorie targets
- Number Base Converter — Binary, hex, octal, decimal & any base
About these tools
The problem with most online calculators is not the arithmetic — it is that they hand back a single number with no working. If a loan calculator tells you your payment is £642.31 you have no way to sanity-check it, and no idea how much of that is interest in year one versus year ten.
These calculators always show the derivation: the formula used, the intermediate values, and where it helps, a full schedule or breakdown table you can copy into a spreadsheet. The loan tool prints a month-by-month amortisation; the compound interest tool separates contributions from growth; the percentage tool shows every one of the six distinct questions people mean when they say “percentage”.
They are also deliberately unit-aware and locale-aware: currency and number formatting follow your browser’s locale, dates respect your timezone, and unit conversion carries enough precision to survive round-tripping.
Frequently asked questions
Are these calculators free to use?
Yes, entirely free with no sign-up and no limits.
How accurate are the financial calculations?
They use the standard closed-form formulas — the annuity payment formula for loans and EMIs, and the compound interest formula with periodic contributions for savings — computed in double precision and rounded only for display.
Is my financial information sent anywhere?
No. Every figure you enter stays in your browser; nothing is transmitted, stored on a server, or shared.
Can I see the working, not just the answer?
Yes — each calculator shows the formula it used and a breakdown of the result, plus a full schedule where one applies.
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