Calculators
Everyday math with the formula shown and the working visible — percentages, loans, health, dates and pay. Your numbers are processed entirely in your browser; financial and health inputs never touch a server.
- Percentage Calculator To find X% of a number, multiply the number by X ÷ 100
- Percentage Change Calculator Percentage change = (new − old) ÷ old × 100
- EMI Calculator EMI = P × r × (1+r)ⁿ ÷ ((1+r)ⁿ − 1), where r is the monthly rate and n the number of months.
- BMI Calculator BMI = weight (kg) ÷ height (m)²
- Age Calculator Your exact age is the calendar difference between today and your date of birth
- Tip Calculator Tip = bill × tip% ÷ 100
- Discount Calculator Final price = original × (1 − discount% ÷ 100)
- Compound Interest Calculator Future value = P × (1 + r/n)^(n×t)
- Simple Interest Calculator Simple interest = principal × rate × time ÷ 100
- Hourly to Salary Calculator Annual salary = hourly rate × hours per week × 52
Frequently asked questions
Are these calculators accurate?
Yes — each uses the standard published formula (EMI amortization, WHO BMI ranges, compound interest), states it on the page, and shows the arithmetic under every result so you can verify it.
Is my financial or health data uploaded anywhere?
No. Every calculator runs as JavaScript in your browser. Loan amounts, body measurements and birthdates never leave your device — the pages even work offline.
Why use these instead of asking an AI chatbot?
Deterministic math: a calculator applies the exact formula every time and shows its working. Language models can make arithmetic slips, and typing your salary or health details into a chatbot shares them with a server — these tools don’t.