Percentage of a Number
(Percentage รท 100) ร Number
Example: 20% of 150 = 30.
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Free Online Percentage Calculator
Calculate Percentages Instantly & Accurately
Find percentages, percentage increase or decrease, percentage change, percentage difference, and add or subtract percentages from any value.
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Six calculator modes
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Instant results
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Mobile friendly
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No sign-up
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Free Tool
Percentage Calculator
Choose a calculation type below
Basic Percentage
What is X% of Y?
Example: What is 20% of 150?
Result
Enter a percentage and a number to see the result.
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Find the Percentage
X is What Percentage of Y?
Example: 30 is what percentage of 150?
Result
Enter two numbers to calculate the percentage.
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Increase or Decrease
Percentage Change Calculator
Calculate the percentage change from an original value to a new value.
Percentage Change
Enter the original and new values.
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Increase a Value
Add a Percentage to a Number
Example: Add 20% to 150.
New Value
Enter a number and percentage.
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Decrease a Value
Subtract a Percentage from a Number
Example: Subtract 20% from 150.
New Value
Enter a number and percentage.
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Compare Two Values
Percentage Difference Calculator
Compare the difference between two values relative to their average.
Percentage Difference
Enter two values to compare them.
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Browser-Based Calculation
Calculations are performed directly in your browser using JavaScript. No sign-up is required.
Quick Reference
Common Percentage Formulas
Use these formulas to understand how common percentage calculations work.
Find What Percentage
(Part รท Whole) ร 100
Example: 30 is 20% of 150.
Percentage Change
((New โ Old) รท |Old|) ร 100
Positive results indicate an increase; negative results indicate a decrease.
Add Percentage
Number ร (1 + Percentage รท 100)
Useful for markups, growth and increases.
Subtract Percentage
Number ร (1 โ Percentage รท 100)
Useful for discounts and reductions.
Percentage Difference
|A โ B| รท ((|A| + |B|) รท 2) ร 100
Compares two values relative to their average magnitude.
Percentage Guide
Free Online Percentage Calculator
A percentage calculator helps express one quantity as a part of one hundred. Percentage calculations are commonly used for discounts, price changes, exam scores, financial comparisons, business analysis, statistics, growth rates and everyday numerical tasks.
This calculator includes multiple modes so you can solve common percentage questions without manually rearranging formulas. You can calculate a percentage of a number, determine what percentage one value is of another, measure percentage change, add or subtract a percentage, and compare two values using percentage difference.
How to Calculate a Percentage of a Number
To calculate a percentage of a number, convert the percentage into decimal form by dividing it by 100, then multiply by the number. For example, to find 20% of 150, multiply 0.20 by 150. The result is 30.
How to Calculate Percentage Increase or Decrease
Percentage change compares the difference between a new value and an original value with the original value. A positive result represents an increase, while a negative result represents a decrease.
For example, if a value rises from 100 to 125, the difference is 25. Dividing 25 by the original value of 100 and multiplying by 100 gives a 25% increase.
Percentage Change vs Percentage Difference
Percentage change and percentage difference are not the same calculation. Percentage change uses an original value as the reference point. Percentage difference is generally used when comparing two values without treating one as the original reference value.
The percentage difference calculation compares the absolute difference between two values with their average. This makes the comparison symmetric: swapping the first and second values does not change the percentage difference result.
Common Uses of Percentage Calculations
Shopping Discounts
Calculate sale prices after percentage discounts.
Business Growth
Compare changes in sales, revenue or costs.
Exam Scores
Convert obtained marks into percentage scores.
Price Changes
Measure percentage increases or decreases in prices.
Important Note
This calculator is intended for general informational use. For financial, tax, legal, accounting or other high-stakes decisions, verify calculations using applicable official rules and professional guidance.
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FAQ
Frequently Asked Questions
Divide the percentage by 100 and multiply
by the number. For example, 20% of 150 is 30.
Divide the first number by the second number
and multiply the result by 100.
Subtract the original value from the new value,
divide by the original value, and multiply by 100.
Percentage difference compares the absolute
difference between two values with their average,
then multiplies the result by 100.
Yes. The percentage calculator is free
to use online.