Three common percentage problems in one tool: what is A% of B, A is what percent of B, and the percentage change from A to B.
How the percentage calculator works
A% of B = A × B ÷ 100. A is what % of B = A ÷ B × 100. Percentage change = (B − A) ÷ |A| × 100.
Example
20% of 150 is 30. The number 30 is 20% of 150. A move from 80 to 100 is a 25% increase.
Frequently asked questions
How do I add a percentage to a number?
Multiply the number by 1 plus the percentage as a decimal. To add 15%, multiply by 1.15.
Why does a 50% fall followed by a 50% rise not return to the start?
Because the second change applies to a smaller number. 100 falls to 50, and a 50% rise takes it only to 75.
What is the difference between percent and percentage points?
Going from 10% to 12% is a rise of 2 percentage points, but a 20% relative increase.