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Start with the wording of your problem: a percent of a number, one number as a percent of another, percentage change, add percent, subtract percent, or percent off.
Free online percent calculator
Percentage Calculator
Use this percentage calculator to find a percent of a number, work out what percent one number is of another, calculate a percentage of a percentage, check percentage change, or find percent off in one clear place.
Percentage calculator
Choose a percentage calculation
Enter the numbers you know. The answer, formula, and steps update instantly.
Answer
20% of 80
1620% of 80 is 16.
Formula
(percentage / 100) x value- Convert 20% to 0.2.
- Multiply 80 by 0.2.
- Result: 16.
How it works
How to use the percentage calculator
Pick the wording that matches your question, enter the numbers, then check the answer and working.
Enter only the numbers you know
The percentage calculator updates as you type, so you can change the percent, base number, part, total, old value, new value, or price without restarting.
Check the answer and formula
Use the answer card for the result, then check the formula and working underneath if you need to show how the percentage was calculated.
Want to understand the methods before entering numbers? Read how to calculate percentages for worked examples, mental shortcuts, and a formula chooser.
Common percentage questions
Common percentage examples
These are the main percentage questions this page is designed to answer.
| Task | Example | Formula | Answer |
|---|---|---|---|
| Find a percentage of a number | 20% of 80 | (percentage / 100) x number | 16 |
| Find what percent one number is of another | 12 is what percent of 60? | (part / total) x 100 | 20% |
| Find a percentage of a percentage | 20% of 50% | (first percentage / 100) x second percentage | 10% |
| Find percentage change | 100 to 125 | ((new - old) / old) x 100 | 25% increase |
| Add or subtract a percentage | 80 plus 20% | number x (1 +/- percentage / 100) | 96 |
| Find a sale price | 25% off 40 | price x (1 - percentage / 100) | 30 |
Method
How to calculate percentages without guessing
The right formula depends on whether you are finding a share, comparing two numbers, or changing a number by a percent.
What is 15% of 200?
Find a percent of a number
Change 15% into 0.15, then multiply 0.15 by 200.
percentage / 100 x number15% of 200 is 30.What percent is 12 of 60?
Compare one number with another
Divide 12 by 60, then multiply the answer by 100.
part / total x 10012 out of 60 is 20%.What is the percentage change from 100 to 125?
Calculate percentage change
Subtract the old value from the new value, divide by the old value, then multiply by 100.
(new - old) / old x 100100 to 125 is a 25% increase.What is 20% of 50%?
Find a percentage of a percentage
Change 20% into 0.20, then multiply 0.20 by 50%.
first percentage / 100 x second percentage20% of 50% is 10%.Formulas
Percentage formulas for each type of question
Most percentage searches are a small set of repeatable formulas with different wording.
Percent of a number
percentage / 100 x numberUse this when the question is written like "what is 20% of 80?", "find 15 percent of 200", or "calculate percentage of a number".
Part as a percentage
part / total x 100Use this when you know the part and the total, and you want to answer "X is what percent of Y?"
Percentage of a percentage
first percentage / 100 x second percentageUse this when both values are percentages. For example, 20% of 50% is 10%.
Percentage change
(new - old) / old x 100Use this for percentage increase, percentage decrease, growth, decline, before-and-after numbers, and change over time.
Add or subtract a percentage
value x (1 +/- percentage / 100)Use this when a number is increased or reduced by a percentage, such as adding 20% or subtracting 15%.
Percent off
price x (1 - percentage / 100)Use this for discounts, sale prices, coupon savings, and price reductions.
Choose the right page
Which percentage calculator should you use?
This calculator handles the common cases. Use a focused calculator when your question has a narrower meaning.
- percentage increase calculatorfor growth, raises, traffic increases, and before-to-after gains
- percentage difference calculatorfor comparing two values without treating one as the original
- percentage change calculatorfor increases, decreases, and change over time
- percent off calculatorfor discounts, sale prices, and savings
Use the right tool
When this percentage calculator is enough
A broad percent calculator is best for everyday percentage questions. Some specialist topics need a narrower tool.
General percentage questions
Use this calculatorUse this calculator for everyday percentage questions, quick percentage finder checks, and mixed percent problems.
A very specific percentage task
Use a focused calculatorA dedicated page can give more examples when the question is specifically about percentage increase, percentage difference, percentage change, or percent off.
Health or finance percentages
Use a specialist sourceBody fat, BMI, APR, APY, tax, loan, and interest percentage questions need extra context because the result may affect health or money decisions.
Avoid mistakes
Common percentage mistakes
These are the errors that make percentage answers look plausible but wrong.
| Mistake | Better check |
|---|---|
| Adding percentages together when they come from different totals | Check the base number first. 20% of 100 and 20% of 50 are not the same amount. |
| Confusing percent change with percentage points | A move from 10% to 15% is a 5 percentage point change, but a 50% relative increase. |
| Using the new value as the base for percentage increase | For percentage change, divide by the original value unless your problem says otherwise. |
| Treating rounded answers as exact | Round only at the end when precision matters, especially for money, rates, or reports. |
FAQ
Percentage calculator questions
Short answers for common percent calculator searches.
How do you calculate a percentage of a number?
Divide the percentage by 100, then multiply by the number. For example, 20% of 80 is 0.20 x 80, which equals 16.
How do you find what percent one number is of another?
Divide the part by the total, then multiply by 100. For example, 12 out of 60 is 12 / 60 x 100, which equals 20%.
How do you calculate a percentage of a percentage?
Turn the first percentage into a decimal, then multiply it by the second percentage. For example, 20% of 50% is 0.20 x 50%, which equals 10%.
How do you calculate percentage change?
Subtract the old value from the new value, divide by the old value, then multiply by 100. A positive answer is an increase, and a negative answer is a decrease.
Is percent the same as percentage?
In everyday calculator use, yes. Percent means per 100, and percentage is the share expressed as a percent.
What is the easiest percentage formula?
The most common formula is percentage / 100 x value. Use it when you want to find a percent of a number.
Can this calculator work out percent off?
Yes. Use the percent off mode to subtract a discount percentage from the original price and see the final price.