What is X% of Y?
Use this calculation when you want to find a percentage of a number, such as 20% of 150 or 8% of 240.
Result
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Example: 20% of 150 = 30
Free Online Calculators
Percentage Calculator
Use this free Percentage Calculator to solve common percentage problems quickly. You can calculate what percentage of a number is, find what percent one number is of another, and work out percentage increases, decreases, and overall percent change.
Percentage calculations show up everywhere in daily life, from discounts and tax to loan comparisons, test scores, commissions, price changes, and investment returns. This page is designed to keep those calculations simple and easy to understand.
If you are working on shopping or pricing scenarios, you may also want to use the Discount Calculator or Sales Tax Calculator. For finance-related comparisons, tools like the ROI Calculator and Loan Calculator can also help.
This calculator is intended for general educational and informational use.
The tools below cover the most common percentage questions. Enter your values and the result updates automatically.
X is what percent of Y?
Use this when you already have two numbers and want to know what percentage the first number represents of the second.
Result
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Example: 30 is 25% of 120
Percentage increase
Use this to measure how much a value has increased relative to the original value.
Result
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Example: from 80 to 100 = 25% increase
Percentage decrease
Use this to measure how much a value has decreased relative to the original value.
Result
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Example: from 200 to 150 = 25% decrease
Percent change
Use this when you want the overall percentage change between two values, whether the result is positive or negative.
Result
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Example: from 120 to 150 = 25% change
How percentage calculations work
A percentage is a proportion out of 100. For example, 20% means 20 out of every 100 units. Because percentages are based on 100, they are useful for comparing values across many everyday situations.
Percentages are used in shopping, tax, tips, grades, statistics, business reporting, finance, and investment analysis. They are also common whenever you need to compare change over time.
Common percentage formulas
What is X% of Y? = (X ÷ 100) × Y
X is what percent of Y? = (X ÷ Y) × 100
Percentage increase = ((New − Original) ÷ Original) × 100
Percentage decrease = ((Original − New) ÷ Original) × 100
Percent change = ((New − Original) ÷ Original) × 100
These formulas are simple, but the right one depends on the question you are trying to answer.
Worked percentage examples
Example 1: basic percentage
What is 20% of 150?
(20 ÷ 100) × 150 = 30
Example 2: what percent
30 is what percent of 120?
(30 ÷ 120) × 100 = 25%
Example 3: increase
A price goes from 80 to 100.
((100 − 80) ÷ 80) × 100 = 25% increase
Example 4: decrease
A price goes from 200 to 150.
((200 − 150) ÷ 200) × 100 = 25% decrease
Common uses for percentage calculations
- Shopping and discounts: work out sale prices and savings.
- Sales tax and tips: calculate tax or tip amounts on a bill.
- Grades and test scores: see what portion of answers were correct.
- Price comparisons: measure increases or decreases over time.
- Finance and investing: compare returns, rate changes, or performance.
- Business reporting: analyze growth, decline, and ratio-based metrics.
For some of these use cases, related calculators such as the Discount Calculator, Sales Tax Calculator, Tip Calculator, and ROI Calculator may be even more specific.
Percentage increase vs percentage decrease vs percent change
These terms are related, but they are not always used in exactly the same way.
- Percentage increase is used when the new value is higher than the original.
- Percentage decrease is used when the new value is lower than the original.
- Percent change is a broader term that can be positive or negative depending on the direction of the change.
If you want a neutral measure that works in either direction, use the percent change tool.
Related calculators
Explore other Calc Nest tools that are often useful alongside this Percentage Calculator.
Frequently asked questions
How do I calculate a percentage of a number?
Divide the percentage by 100 and multiply it 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 first number by the second number and multiply by 100. For example, 30 out of 120 is 25%.
What is the difference between percentage increase and percentage decrease?
Percentage increase is used when the new value is higher than the original, while percentage decrease is used when the new value is lower.
What is percent change?
Percent change is the overall relative change from an original value to a new value. It can be positive or negative.
Can percentages be negative?
Yes. A percentage change can be negative when the new value is lower than the original value.
Why does the calculator sometimes show a negative result?
A negative result usually means the value has decreased compared with the original value, especially in the percent change calculation.
Can I use this Percentage Calculator on mobile?
Yes. The page is designed to work on phones, tablets, and desktop devices.
Does this page store my numbers?
No account is required, and the calculations are handled directly in your browser.