Compound Interest Calculator
Calculate how investments grow using compound interest. Formula: A = P(1 + r/n)^(nt).
All Calculators
Free online calculators with verified formulas, worked examples, and tier-1 source citations. 9 calculators available.
Finance Calculators · Percentage Calculators · Health Calculators
Finance
Mortgage Calculator
Calculate monthly mortgage payments and see the full amortization schedule. Formula: M = P × r(1+r)^n / ((1+r)^n − 1).
Percentages
Percentage of Number Calculator
Find a percentage of any number. Example: 10% of 200 = 20.
What Percent Of Calculator
Find what percentage one number is of another. Example: 25 is 25% of 100.
Percentage Change Calculator
Calculate percentage increase or decrease between two values.
Discount Calculator
Calculate discounted prices and savings from a percentage discount.
Tip Calculator
Calculate tip amounts and totals from bill amount and tip percentage.
Health
BMI Calculator
Calculate your Body Mass Index (BMI) in metric or imperial units. CDC standard categories: underweight, normal, overweight, and obese classes I–III.
BMR Calculator
Calculate your Basal Metabolic Rate (BMR) and Total Daily Energy Expenditure (TDEE) using the Mifflin–St Jeor equation. Includes all 5 activity levels and Harris-Benedict comparison.