Percentage Calculator
The Percentage Calculator handles the three most common percentage questions in one place: X% of Y, X as a percentage of Y, and the percentage change between two values. Results update live as you type.
What this means
A percentage is a fraction of 100. '10% of 200' means 10 out of every 100 units of 200, which equals 20. Percentages let you compare amounts that are otherwise different sizes.
How we calculate it
Formula
X% of Y = Y × X ÷ 100. X as % of Y = X ÷ Y × 100. Change = (New − Old) ÷ |Old| × 100.Worked example
What is 10% of 200?
- 1200 × 10 ÷ 100
- 2200 × 0.10 = 20
- 3So 10% of 200 is 20.
Important assumptions
- Percentage change uses the absolute value of the original number as the base.
Frequently asked questions
What is 10% of 50?
5. Multiply 50 by 0.10. You can also divide 50 by 10 because 10% is one tenth.
How do I add a percentage to a number?
Multiply the number by (1 + pct ÷ 100). For example, 100 increased by 15% = 100 × 1.15 = 115.
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