Percentage Calculator
Calculate percentages, percentage change, increase, decrease, and solve percentage problems with our free calculator.
What is X% of Y?
X is what percent of Y?
Percentage Change
Percentage Difference Calculator
Calculates the percentage difference between two values.
Understanding Percentages
A percentage is a way of expressing a number as a fraction of 100. The word "percent" comes from the Latin "per centum," meaning "by the hundred." Percentages are used extensively in everyday life, from calculating discounts while shopping to understanding financial data, exam scores, and statistical information.
Our percentage calculator makes it easy to solve common percentage problems quickly and accurately. Whether you need to find what percentage one number is of another, calculate a percentage of a value, or determine percentage change, this tool has you covered.
How to Calculate Percentages
There are several common percentage calculations you might need to perform:
Finding a Percentage of a Number
To find X% of Y, use this formula:
Result = (X/100) × Y
Example: What is 25% of 200?
Result = (25/100) × 200 = 0.25 × 200 = 50
Finding What Percent X is of Y
To find what percentage X is of Y, use:
Percentage = (X/Y) × 100
Example: 50 is what percent of 200?
Percentage = (50/200) × 100 = 0.25 × 100 = 25%
Calculating Percentage Change
Percentage change measures the relative change between two values:
Change = ((New - Old)/Old) × 100
Example: From 100 to 150
Change = ((150 - 100)/100) × 100 = 50%
Common Percentage Applications
- Discounts: Calculate sale prices by finding the discount percentage
- Tips: Calculate restaurant tips as a percentage of the bill
- Grades: Convert test scores to percentages
- Finance: Understand interest rates and investment returns
- Statistics: Analyze data using percentage comparisons
Percentage Tips and Tricks
Here are some mental math shortcuts for common percentages:
- 10%: Divide by 10 (move decimal one place left)
- 5%: Find 10% and divide by 2
- 15%: Find 10% + 5%
- 20%: Find 10% and double it
- 25%: Divide by 4
- 50%: Divide by 2
Frequently Asked Questions
How do I calculate percentage increase?
Subtract the original value from the new value, divide by the original value, and multiply by 100. Formula: ((New - Original) / Original) × 100
How do I calculate percentage decrease?
Subtract the new value from the original value, divide by the original value, and multiply by 100. A negative result indicates a decrease.
What is the difference between Percentage Change and Percentage Difference?
Percentage Change measures the change relative to an initial value (e.g., price increase). Percentage Difference compares two values relative to their average, useful when neither value is the "start" or "end" (e.g., difference between two distinct measurements).
What is the Percentage Difference Formula?
The formula is: |V1 - V2| / ((V1 + V2)/2) × 100.
What is the difference between percentage and percentile?
A percentage represents a portion out of 100, while a percentile indicates the rank of a value compared to other values in a dataset.