Percentage Calculator

Calculate percentages easily - find percentage of a number, what percent one number is of another, percentage change, increase, or decrease with step-by-step solutions.

Calculate Percentage

What do you want to calculate?

Percentage (%)

Number

Understanding Percentages

What is a Percentage?

A percentage is a way of expressing a number as a fraction of 100. The symbol % means “per hundred” or “out of 100”. For example, 25% means 25 out of 100, or 25/100, which equals 0.25 as a decimal.

Common Percentage Values

10%

0.1 or 1/10

25%

0.25 or 1/4

50%

0.5 or 1/2

75%

0.75 or 3/4

Real-World Applications

• Shopping: Calculate discounts and sales tax
• Finance: Interest rates, investment returns, and loan calculations
• Statistics: Data analysis and probability
• Grades: Academic scores and performance metrics
• Business: Profit margins, growth rates, and market share

Quick Mental Math Tips

• To find 10% of any number, move the decimal point one place left
• To find 5%, calculate 10% and divide by 2
• To find 15%, calculate 10% and add half of it
• To find 20%, calculate 10% and double it
• To find 25%, divide by 4

Pro Tip: When dealing with percentage changes, remember that a 50% decrease followed by a 50% increase doesn't return you to the original value. For example: 100 → 50 (50% decrease) → 75 (50% increase). This is because percentages are calculated based on the current value, not the original.