What is 20% of 150?
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Percentage Calculator
Get a clear percentage answer in seconds. Choose a calculation, enter your numbers, and see the result with the formula behind it.
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What is X% of Y?
Find a percentage of any number.
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Simple examples
Try a common calculation, then replace the values with your own.
25 is what percent of 200?
12.5%What is the change from 80 to 100?
25% increaseCalm, clear, useful
Why use this percentage calculator?
It gives you the answer first, then shows enough detail to trust it.
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Results and formulas appear as soon as you calculate.
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Three simple steps
How to use the calculator
No setup and no formula memorization required.
- 01
Choose a calculation
Pick percentage of a number, what percent, percentage change, or increase/decrease.
- 02
Enter your values
Type any whole number, decimal, or negative value that fits your situation.
- 03
Read the answer
See the result, plain-English explanation, and formula used to calculate it.
Understand the math
Percentage formulas at a glance
Use these four formulas whenever you need to check a result by hand.
Percentage of a number
Number × Percentage ÷ 100150 × 20 ÷ 100 = 30
Open this calculatorWhat percent?
Part ÷ Whole × 10025 ÷ 200 × 100 = 12.5%
Open this calculatorPercentage change
(New − Original) ÷ |Original| × 100(100 − 80) ÷ 80 × 100 = 25%
Open this calculatorIncrease or decrease
Number × (1 ± Percentage ÷ 100)200 × (1 + 15 ÷ 100) = 230
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Clear answers
Frequently asked questions
How do I calculate a percentage of a number?
Convert the percentage to a decimal by dividing it by 100, then multiply by the number. For example, 20% of 150 is 0.20 × 150 = 30.
How do I find what percent one number is of another?
Divide the part by the whole and multiply by 100. If the part is 25 and the whole is 200, the answer is 12.5%.
What is the formula for percentage change?
Subtract the original value from the new value, divide by the absolute original value, and multiply by 100. A positive result is an increase and a negative result is a decrease.
Can I use decimals and negative numbers?
Yes. The calculator accepts decimals and negative values. Percentage change from an original value of zero is undefined, so the tool explains that case instead of showing infinity.
Does this calculator save my numbers?
No. Calculations happen locally in your browser. Your inputs are not uploaded, stored, or included in analytics.
Why might my answer look slightly different from a spreadsheet?
This tool shows up to ten decimal places and removes unnecessary zeros. A spreadsheet may use a different display precision while keeping a similar underlying value.
Short, practical guides
Learn percentages with confidence
Understand the method, avoid common mistakes, and apply percentages to everyday questions.
How to calculate a percentage
A straightforward guide to parts, wholes, percentages, and the three formulas you will use most.
Read the guide →How to calculate percentage change
Measure increases and decreases correctly and understand what happens when the original value is zero.
Read the guide →How to calculate a discount
Turn a sale percentage into the amount saved and the final price you will pay.
Read the guide →Keep the answer, skip the clutter.
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