Percentage Calculator
Calculate percent of a number, percentage change, and what percentage one value is of another.
What this calculator does
Use this calculator for common percentage questions: finding a percentage of a number, measuring percentage increase or decrease, or finding what percent one number is of another. It is useful for discounts, tips, price changes, grades, budgets, and quick comparisons.
Inputs and results
The Calculation menu changes how the two number fields are interpreted. In Percentage of a number mode, the first number is the percent and the second number is the whole. In Percentage change mode, the first number is the original value and the second number is the new value. In What percentage mode, the first number is the part and the second number is the whole.
The result shows the percentage answer and a short label that describes the calculation. For percentage change, a positive result means an increase and a negative result means a decrease.
Worked examples
If a jacket costs $80 and is discounted by 25%, enter 25 and 80 in Percentage of a number mode. The discount amount is $20. If a bill rises from $120 to $138, use Percentage change mode with 120 and 138. The increase is 15%.
If you answered 42 questions correctly out of 50, use What percentage mode with 42 and 50. The result is 84%.
Tips for interpreting results
For a percent of a number, remember that the calculator gives the percentage amount, not the final sale price after subtracting a discount. For percentage change, the original value cannot be zero because there is no meaningful starting point for the comparison. Small original values can produce very large percentage changes.
Frequently asked questions
How do I find a percentage of a number?
Multiply the number by the percentage and divide by 100. For example, 20% of 150 is 30.
How is percentage change calculated?
Subtract the original value from the new value, divide by the original value, and multiply by 100.
What is the difference between percentage points and percent change?
Percentage points are a direct subtraction between two percentages. Percent change compares the size of the change with the starting value.
Can the result be negative?
Yes. In percentage change mode, a negative result means the new value is lower than the original value.