Percentage Calculator
Use this percent calculator to find percentages, percentage change, increases, decreases, discounts, and reverse percentage values.
Percentage calculator
Result
30
15% of 200 is 30.
How to calculate percentages
A percentage means a number out of 100. This calculator covers the most common percentage tasks: finding a percent of a number, finding what percent one number is of another, calculating percentage change, and increasing or decreasing a value by a percentage.
Percentage formulas
- Find a percent of a number:
(percentage / 100) x number - Find what percent one number is of another:
(part / total) x 100 - Find percentage change:
((new value - old value) / old value) x 100 - Increase by a percentage:
number x (1 + percentage / 100) - Decrease by a percentage:
number x (1 - percentage / 100)
Common percentage examples
| Question | Formula | Answer |
|---|---|---|
| What is 15% of 200? | 15 / 100 x 200 | 30 |
| 30 is what percent of 200? | 30 / 200 x 100 | 15% |
| What is the percentage change from 80 to 100? | (100 – 80) / 80 x 100 | 25% increase |
| What is 250 increased by 10%? | 250 x 1.10 | 275 |
When to use a percentage calculator
Percentages are used in discounts, sales tax, interest rates, price changes, grades, statistics, business growth, finance, health data, and everyday comparisons. A percentage calculator helps avoid mental math errors and shows the exact formula behind the result.
Percentage calculator FAQ
What is the easiest way to calculate a percentage?
Divide the percentage by 100, then multiply by the number. For example, 20% of 80 is 0.20 x 80 = 16.
How do I calculate percentage increase?
Subtract the old value from the new value, divide by the old value, then multiply by 100.
How do I calculate a discount percentage?
Multiply the original price by the discount percentage divided by 100. Subtract that discount amount from the original price.
Can percentages be over 100?
Yes. A percentage over 100 means the value is greater than the original whole. For example, 150% of 200 is 300.