What is 20% of 150?
150 × 20 ÷ 100 = 30
Answer: 30
Percentage Calculator
Find a percentage of a number, what percent one number is of another, or the percentage change between two values.
Result
Enter both values and select Calculate to see the result.
Result
Enter both values and select Calculate to see the result.
Result
Enter both values and select Calculate to see the result.
Runs in your browser — nothing you enter is sent to a server.
How the Percentage Calculator works
A percentage is a number expressed as a fraction of 100 — 20% means 20 out of every 100. This calculator covers the three questions people ask most often:
- X% of Y — how much a percentage of a value is, such as a 15% tip on a bill.
- X is what % of Y — what share one value is of a total, such as a test score.
- Percentage change — how much a value rose or fell, such as a price change.
Choose the calculation, enter both values and select Calculate. The result shows the working, so you can check it or repeat it by hand. Results are rounded to at most 6 decimal places.
Formulas
Percentage of a value
result = (p ÷ 100) × V
Where:
- p
- The percentage
- V
- The value you take the percentage of
What percent one value is of another
p = (part ÷ whole) × 100
Where:
- part
- The value being compared
- whole
- The total reference value (not 0)
Percentage change
change = ((new − old) ÷ |old|) × 100
Where:
- old
- The original value (not 0)
- new
- The new value
A positive result is an increase and a negative result is a decrease. Dividing by the absolute value keeps that true when the original value is negative.
Examples
45 out of 60 on a test — what percentage is that?
45 ÷ 60 × 100 = 75
Answer: 75%
A price rises from $80 to $100
(100 − 80) ÷ 80 × 100 = 25
Answer: a 25% increase
Rent falls from 1,200 to 1,050
(1,050 − 1,200) ÷ 1,200 × 100 = −12.5
Answer: a 12.5% decrease
Frequently asked questions
How do I calculate a percentage of a number?
Multiply the number by the percentage, then divide by 100. For example, 15% of 80 is 80 × 15 ÷ 100 = 12.
Is a percentage increase the same as a percentage point increase?
No. If an interest rate goes from 4% to 5%, it rose by 1 percentage point, but by 25 percent, because 1 is 25% of 4.
Why does a 50% decrease followed by a 50% increase not return to the original value?
Each percentage applies to a different starting value. 100 decreased by 50% is 50; 50 increased by 50% is 75, not 100.
Can I use negative numbers or decimals?
Yes. Enter decimals with a dot, such as 12.5. Negative values work in every mode, but the total in “X is what % of Y” and the original value in “Percentage change” can’t be 0, because dividing by zero has no answer.
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