How it works
- X% of Y = X ÷ 100 × Y.
- A is what % of B = A ÷ B × 100.
- Percentage change from A to B = (B − A) ÷ |A| × 100.
Worked examples
15% of 200
What is 15% of 200?
- Convert the percentage to a decimal: 15 ÷ 100 = 0.15.
- Multiply: 0.15 × 200.
Answer: 30
Try this exampleA price rising from 80 to 100
What is the percentage increase when a price goes from 80 to 100?
- Change = 100 − 80 = 20.
- Divide by the starting value: 20 ÷ 80 = 0.25.
- Multiply by 100.
Answer: A 25% increase
Try this exampleFrequently asked questions
What is the difference between percent and percentage points?
Going from 10% to 15% is a 5 percentage-point increase but a 50% relative increase.
Why can't I calculate change from zero?
A change from 0 is undefined as a percentage because you would be dividing by zero.
Results are estimates for general information and are not financial, medical or professional advice.