How to use the Percentage Calculator
- Find the line that matches your question.
- Type your two numbers.
- Read the answer on the right. It updates as you type.
Questions
How do I calculate a percentage of a number?
Multiply the number by the percent and divide by 100. For example, 15% of 200 is 200 × 15 ÷ 100 = 30.
How do I calculate percentage change?
Subtract the old value from the new value, divide by the old value and multiply by 100. From 80 to 100 is a 25% increase.
How do I add a percentage, like tax?
Use the last line. 50 plus 20% is 60, and 50 minus 20% is 40.
Why is a 50% drop not undone by a 50% rise?
Because the second percentage is taken from a smaller number. 100 minus 50% is 50, and 50 plus 50% is only 75.