Percentage Calculator — Calculate What Percentage One Number Is of Another
Free percentage calculator. Work out what is X% of Y, what percentage one number is of another, and percentage increases and decreases — with step-by-step working shown so you can verify every result. Pick a mode below, type two numbers, and the answer updates instantly as you type.
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How it works
- Divide the percentage by 100 to turn it into a decimal — 15% becomes 0.15.
- Multiply that decimal by the value you are working from.
- To go the other way, divide the part by the whole and multiply by 100.
See it in action
Worked examples
What is 10% of 50?
- Turn the percent into a decimal: 10 ÷ 100 = 0.10
- Multiply by the value: 0.10 × 50 = 5
Answer: 5
Finding a simple tenth of anything — a quick tip estimate, a 10% service fee, or a 10% sample of a group.
What is 15% of 200?
- Turn the percent into a decimal: 15 ÷ 100 = 0.15
- Multiply by the value: 0.15 × 200 = 30
Answer: 30
A standard 15% tip on a $200 banquet bill, or a 15% commission on $200 of sales.
What is 25% of 80?
- Turn the percent into a decimal: 25 ÷ 100 = 0.25
- Multiply by the value: 0.25 × 80 = 20
Answer: 20
A quarter of a class of 80 students, or a 25% down payment on an $80 item.
What is 30% of 500?
- Turn the percent into a decimal: 30 ÷ 100 = 0.30
- Multiply by the value: 0.30 × 500 = 150
Answer: 150
A 30% discount on a $500 product, or 30% of a 500-person survey responding “yes”.
What is 5% of 1000?
- Turn the percent into a decimal: 5 ÷ 100 = 0.05
- Multiply by the value: 0.05 × 1000 = 50
Answer: 50
A 5% sales tax on a $1,000 purchase, or a 5% cash-back reward on $1,000 of spending.
Answers
Frequently asked questions
How do I calculate a percentage of a number?
Divide the percentage by 100 and multiply by the number. For 15% of 200: 15 ÷ 100 = 0.15, and 0.15 × 200 = 30.
How do I work out what percentage one number is of another?
Divide the part by the whole, then multiply by 100. 45 out of 180 is 45 ÷ 180 = 0.25, which is 25%.
Is a 50% increase then a 50% decrease back to the start?
No. 100 increased by 50% is 150, and 150 decreased by 50% is 75. Percentages always apply to the value in front of them at that moment.
Can percentages be greater than 100%?
Yes. 250% of 40 is 100. Anything above 100% simply means more than the whole.
Do I need to press a button to calculate?
No. Results update instantly as you type, with no page reload.
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