Percentage Calculator
Find a percentage of a number, work out what percent one value is of another, measure a percentage increase or decrease, or compare two values using percentage difference.
20% of 500 is 100.
Calculated in your browser. Results are rounded to 4 decimal places.
What Percent Is One Number of Another?
Use the “X of Y %” tab for a score or a completed share. Enter the part first and the whole second. The whole cannot be zero. A part greater than the whole produces a result above 100%, which can be valid for a target exceeded.
- 142 ÷ 50 = 0.84
- 20.84 × 100 = 84
Therefore: A score of 42 out of 50 is 84%.
How to Calculate a Percentage
A percentage represents a value as a part of 100. To calculate a percentage of a number, divide the percentage by 100 and multiply the result by the number.
- 120 ÷ 100 = 0.20
- 20.20 × 500 = 100
Therefore: 20% of 500 is 100.
How to Calculate Percentage Increase
Find the difference between the new and original values, divide it by the original value, then multiply by 100. A negative result means a decrease.
Percentage Difference vs Percentage Change
Percentage change has a direction: it measures how far a new value has moved from an original value. Percentage difference has no starting point — it compares two values against their average, so swapping them gives the same answer.
Use percentage difference when comparing two measurements of equal standing, such as prices at two shops or results from two tests.
- 1|40 − 60| = 20
- 2(40 + 60) ÷ 2 = 50
- 320 ÷ 50 × 100 = 40
Therefore: The percentage difference between 40 and 60 is 40%.
When Is a Percentage Calculator Useful?
- Calculating discounts
- Comparing prices
- Measuring increases or decreases
- Checking test scores
- Analyzing business metrics
- Calculating tips
- Working with statistics
- Comparing numerical changes
Frequently Asked Questions
20% of 500 is 100. Divide 20 by 100 to get 0.20, then multiply 0.20 by 500.
Divide the percentage by 100, then multiply the result by the number. For example, 15% of 80 is 0.15 × 80 = 12.
Subtract the original value from the new value, divide the difference by the original value, then multiply by 100.
Percentage change compares a new value with an original value, so direction matters. Percentage difference compares two values relative to their average, so neither value is treated as the original.
Percentage change divides by the original value. Dividing by zero is undefined, so there is no meaningful percentage increase from 0 to any other number.