Percentage Calculator

Use this free percentage calculator for percent, percent change, discount, or tip calculations.
About Percentage Calculations

Percentages are a way to express a number as a fraction of 100.

Common Applications:

  • Basic Percentage: Find X% of a number
  • Percentage Change: Increase or decrease by X%
  • Discounts: Calculate sale prices and savings
  • Tips: Calculate restaurant tips and service charges

Quick Tips:

  • 10%: Move decimal one place left
  • 20%: Double 10% value
  • 25%: Divide by 4
  • 50%: Divide by 2
  • 100%: The entire amount

Common Tip Rates:

  • 15%: Standard service
  • 18%: Good service
  • 20%: Excellent service
  • 25%+: Outstanding service

Remember that percentages are always calculated relative to the original amount unless specified otherwise.

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How our percentage calculator works

1

Choose your problem type

Select from percent of a number, percent increase, percent decrease, percentage points, or tip calculation. Each mode is tuned for the most common use case.

2

Enter the numbers

Type the values relevant to your problem. The calculator auto-detects the right formula and shows the math step by step.

3

Get the result with explanation

See the final answer plus the formula and the steps used. Useful for checking your own work or learning the underlying math.

Key things to know about our percentage calculator:

  • Percent change formula: ((new - old) / old) x 100. Going from 50 to 60 is a 20% increase, but 60 to 50 is a 16.67% decrease.
  • Percentage points: The arithmetic difference between two percentages. 5% to 7% is a 2 percentage point increase but a 40% relative increase.
  • Everyday use: Use the percentage calculator for tips, discounts, taxes, grades, statistics, and any other percent problem.

For related calculations, try our tip calculator.