Free online calculators
Calculators for the questions that come up every week: percentages, dates, time, money and school math. Every page shows the formula, a worked example and the usual mistakes, so you can check the answer instead of just trusting it.
Money and loans
- Discount CalculatorWork out the sale price, the amount saved and the effective discount when offers stack.
- Tip CalculatorCalculate the tip, the total bill and each person's share when you split it.
- Loan Payment CalculatorEstimate the monthly payment, total interest and yearly balance of a fixed-rate loan.
- Savings CalculatorSee how regular deposits and interest grow a balance over time.
- Compound Interest CalculatorSee how a lump sum grows with interest on interest, at any compounding frequency.
Percentages
- Percentage CalculatorFind X% of a number, what percent one number is of another, or the total behind a percentage.
- Percentage Increase CalculatorFind the percentage increase between two numbers, or raise a number by a percentage.
- Percentage Decrease CalculatorFind the percentage decrease between two numbers, or reduce a number by a percentage.
- Percentage Difference CalculatorCompare two numbers as a percentage when neither one is the starting point.
Age and dates
Math and statistics
Time and hours
School and grades
Pay and salary
Guides to go with these tools
All guides- Article · September 19, 2026Decimal Hours Explained: Why 7:45 Is Not 7.45
- Guide · September 19, 2026How to Add, Subtract, Multiply and Divide Fractions
- Guide · September 19, 2026How to Calculate a Discount and the Sale Price
- Guide · September 19, 2026How to Calculate a Loan Payment
- Guide · September 19, 2026How to Calculate a Percentage
- Guide · September 19, 2026How to Calculate a Tip and Split the Bill