Percentage Calculator
Five everyday percentage questions, answered as you type. Each result shows the formula with your numbers, so you can check the working.
Percent of a number
What percent is it?
Percentage change
Add or subtract a percentage
Percentage difference
Tip: click a result to copy it. Both 1,250.5 and 1.250,5 are understood.
Percentage formulas
Percent of a number: X% of Y = X ÷ 100 × Y.
What percent: A is (A ÷ B × 100)% of B.
Percentage change: (new − old) ÷ |old| × 100.
Percentage difference: |A − B| ÷ ((|A| + |B|) ÷ 2) × 100.
Frequently asked questions
How do I work out a percentage of a number?
Divide the percentage by 100 and multiply by the number. 15% of 240 is 0.15 × 240 = 36.
How do I calculate percentage change?
Subtract the old value from the new value, divide by the old value, and multiply by 100. Going from 80 to 100 is (100 − 80) ÷ 80 × 100 = a 25% increase.
What is the difference between percentage change and percentage difference?
Percentage change has a direction: it compares a new value with an original one. Percentage difference compares two values with neither as the starting point, so it divides by their average.
Why doesn’t a 20% rise followed by a 20% fall get back to the start?
The fall is taken from the larger number. 100 rises 20% to 120, then falls 20% of 120 (24) to 96.