All Calculators

Six 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.

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.

Education

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

Everyday Math

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

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