All Calculators

Sixteen free calculators covering finance, health, education, and everyday math. Every tool on this page shows its formula, a worked example, and a plain-language explanation, not just a number.

Finance

Mortgage Calculator — monthly payment, total interest, and full loan cost from your home price, down payment, rate, and term.

Loan Calculator — monthly payment and total interest for any personal or auto loan.

Compound Interest Calculator — see how your savings or investment grows with compounding.

Health & Fitness

BMI Calculator — Body Mass Index with WHO category and a healthy weight range, in metric or imperial units.

Calorie Calculator — daily calorie needs (BMR and TDEE) for maintaining, losing, or gaining weight.

Pregnancy Due Date Calculator — estimated due date and current week, from your last period or conception date.

Body Fat Calculator — estimate body fat percentage using the US Navy method.

Ideal Weight Calculator — a healthy target weight range based on your height and sex.

Education

GPA Calculator — weighted grade point average from your course credit hours and letter grades.

Final Grade Calculator — the exact score you need on your final to hit your target grade.

Everyday Math

Percentage Calculator — percentage of a number, what percent one number is of another, and percentage change.

Discount Calculator — final price, amount saved, and stacked discounts, instantly.

Age Calculator — exact age in years, months, and days between any two dates, plus days to your next birthday.

Unit Conversion Calculator — convert length, weight, temperature, and volume instantly.

Date Calculator — days between two dates, or add and subtract time from any date.

Time Calculator — add, subtract, or find the duration between two times.