All calculators
Every tool on the site, grouped by category. Each calculator runs entirely in your browser and shows the exact formula, assumptions, and a worked example next to the result.
Finance
About finance calculators →- Mortgage CalculatorEstimate the monthly payment, total interest, and total cost of a fixed-rate mortgage.
- Loan CalculatorCalculate the monthly payment and total interest for any fixed-rate installment loan.
- Compound Interest CalculatorSee how an investment grows with compounding, with optional regular contributions.
- Simple Interest CalculatorCalculate simple (non-compounding) interest on a principal over time.
- Savings Goal CalculatorFind the monthly deposit needed to reach a savings goal by a target date.
- Percentage CalculatorFind what a percentage of a number is, what percent one number is of another, and the percentage change between two values.
- Percentage Increase CalculatorCalculate the percentage increase from a starting value to a new value, or apply an increase directly.
- Percentage Decrease CalculatorCalculate the percentage decrease between two values, or reduce a number by a given percentage.
- Average CalculatorCalculate the arithmetic mean of a set of numbers, along with the count, sum, minimum, and maximum.
- Fraction CalculatorAdd, subtract, multiply, and divide fractions, with results simplified to lowest terms and shown as mixed numbers.
- Ratio CalculatorSimplify a ratio to its lowest terms and see the equivalent proportion per unit.
- Exponent CalculatorRaise any base to any power, including negative and fractional exponents.
- Square Root CalculatorFind the square root of any non-negative number, and check whether it is a perfect square.
- Quadratic Equation CalculatorSolve ax² + bx + c = 0 with the quadratic formula, including the discriminant and complex roots.
- BMI CalculatorCalculate body mass index from height and weight, in metric or imperial units, with the WHO classification.
- BMR CalculatorEstimate basal metabolic rate — the calories your body burns at rest — using the Mifflin–St Jeor equation.
- TDEE CalculatorEstimate total daily energy expenditure — maintenance calories — from BMR and activity level.
Time & Date
About time & date calculators →- Age CalculatorCalculate an exact age in years, months, and days between a date of birth and any date.
- Date Difference CalculatorCount the days, weeks, months, and years between two calendar dates.
- Date Add / Subtract CalculatorAdd or subtract years, months, weeks, and days from any date.
- Business Days CalculatorCount working days (Monday–Friday) between two dates, excluding weekends.
Everyday
About everyday calculators →- Tip CalculatorWork out the tip, total bill, and per-person split for any check.
- Discount CalculatorFind the sale price and savings after a percentage discount.
- Grade CalculatorConvert points earned into a percentage and a letter grade.
- Fuel Cost CalculatorEstimate the fuel needed and total cost of a trip from distance, fuel economy, and price per gallon.