Calculate Percentages
How to Calculate Percentages
Learn how to calculate percentages, percentage of a number, and percentage change.
Percentage of a Number
Multiply the number by the percentage and divide by 100. Example: 15% of 240 = (15 × 240) / 100 = 36.
Number as a Percentage
Divide the part by the whole and multiply by 100. Example: 30 is what % of 240? = (30 / 240) × 100 = 12.5%.
Percentage Change
Subtract the original from the new, divide by the original, and multiply by 100. Example: 80 to 100 = ((100-80)/80) × 100 = 25% increase.
Frequently Asked Questions
How do I calculate 15% of 200?
Divide 15 by 100 to get 0.15, then multiply by 200. The answer is <strong>30</strong>. Alternatively, 10% of 200 is 20, and 5% is 10, so 15% = 20 + 10 = 30.
What is the formula for percentage change?
Percentage change = <strong>((New Value − Original Value) ÷ |Original Value|) × 100</strong>. A positive result indicates an increase; a negative result indicates a decrease.
How do I calculate a percentage increase?
To increase a number by a percentage, multiply it by <strong>(1 + percentage ÷ 100)</strong>. For example, to increase 200 by 10%: 200 × 1.10 = 220.
How do I calculate a percentage decrease?
To decrease a number by a percentage, multiply it by <strong>(1 − percentage 100)</strong>. For example, to decrease 200 by 10%: 200 × 0.90 = 180.
What is 25% as a decimal?
25% as a decimal is <strong>0.25</strong>. To convert any percentage to a decimal, divide by 100.
How do I work out percentages without a calculator?
Break the percentage into easy parts. For example, to find 35% of 80: 10% of 80 = 8, so 30% = 24, and 5% = 4. Therefore 35% = 24 + 4 = <strong>28</strong>.