Find the calculator you need. Free tools for everyday math, money, health, dates, and conversions. Every tool works in your browser and includes a short guide with worked examples.
Math
- CalculatorEveryday arithmetic with a backspace key
- Percentage CalculatorPercent of, change, and difference
- Graphing CalculatorPlot functions and compare curves
Money & Finance
- Loan CalculatorMonthly payment and total interest
- Mortgage CalculatorHome payments with tax and insurance
- Compound InterestSee savings grow over time
- Discount CalculatorNEWSale price, stacked discounts, tax
- Tip CalculatorTip and split the bill
- Stock Fair ValueEstimate value with a DCF model
Health
Dates & Conversions
Which calculator do you need?
- Planning a big purchase? The Loan Calculator and Mortgage Calculator show your monthly payment, the total interest, and how each payment is split between interest and principal.
- Saving or investing? The Compound Interest Calculator shows how regular contributions grow, and the Stock Fair Value Calculator explains how analysts estimate what a company is worth.
- Eating out? The Tip Calculator works out the tip and splits the bill.
- Shopping a sale? The Discount Calculator handles stacked discounts and sales tax.
- Checking your health numbers? The BMI Calculator and Calorie Calculator give standard screening estimates in US or metric units.
- Homework or quick math? Use the Calculator, the Percentage Calculator, or the Graphing Calculator.
- Dates and units? The Age Calculator counts exact years, months, and days, the D-Day & Date Calculator counts days between dates and down to events, and the Conversion Calculator converts between metric and US units.
- Apartment hunting in Korea? The Pyeong Converter turns 평 into square meters and explains advertised sizes.
Every calculator page includes a step-by-step guide with the formula, a worked example, and answers to common questions, so you can understand the result as well as get it.