Percentage Calculator
Calculate percentages easily. Find what percentage one number is of another, calculate percentage increases or decreases, and compute percentages of values.
What is X% of Y?
Result
20
20% of 100 = 20
Formula
(20 ÷ 100) × 100 = 20
Common Calculations
Our percentage calculator handles all common percentage calculations: finding a percentage of a number, calculating percentage increase or decrease, and determining what percentage one number is of another. The calculator displays detailed steps and handles decimal numbers for precision. Whether you're calculating discounts, analyzing data changes, or working on academic problems, this tool provides instant results.
When to Use This Tool
- Calculating discounts and sale prices while shopping
- Determining percentage increases or decreases in data (sales, population, prices)
- Calculating grades and scores as percentages
- Computing interest rates and investment returns
- Figuring out tips and service charges at restaurants
- Analyzing statistical data and survey results
How to Use
Calculate X% of Y
- Enter the percentage you want to calculate (e.g., 15)
- Enter the total number (e.g., 200)
- Click 'Calculate' to see the result (15% of 200 = 30)
- Use copy button to transfer the result
Calculate Percentage Increase/Decrease
- Enter the original value
- Enter the new value
- Click 'Calculate' to see the percentage change
- Positive result indicates increase, negative indicates decrease
Find What Percent A is of B
- Enter the first number (the part)
- Enter the second number (the total)
- Click 'Calculate' to see what percentage the first is of the second
- Example: 30 is what percent of 200? Answer: 15%
Examples
Shopping Discount
Calculate how much you save and what you'll pay on sale
Input
Original price: $150 | Discount: 25%
Result
Discount amount: $37.50 | Final price: $112.50
Population Growth
Track growth rates for demographics, subscribers, or sales
Input
Original: 5000 | New: 6500
Result
Percentage increase: 30%
Test Score
Convert raw scores to percentages for grading
Input
Score: 45 points | Total: 60 points
Result
Percentage: 75% (Grade: B)
Frequently Asked Questions
How do I calculate percentage increase?
Percentage increase = ((New Value - Original Value) / Original Value) × 100. For example, if something grew from 50 to 75, the increase is ((75-50)/50) × 100 = 50%.
What's the difference between percent and percentage points?
Percent is a relative change (e.g., increasing from 10% to 20% is a 100% increase). Percentage points is the absolute difference (10% to 20% is a 10 percentage point increase). Be careful not to confuse them when reading statistics.
How do I reverse a percentage calculation?
If you know the result and percentage, you can find the original: Original = Result / (Percentage / 100). For example, if 30 is 15% of something, the original is 30 / 0.15 = 200.
Why do I get different results with the same percentage?
The context matters. 15% of 100 (base) differs from 15% of 120 (different base). Always verify which number is your reference point (the 100% value) before calculating.
Can decimals be used in percentage calculations?
Yes, percentages can include decimals (e.g., 7.5%). This is common for precise calculations like interest rates, growth rates, and statistical data.
Pro Tips
- •For discounts: Subtract the discount percentage from 100%, then multiply by the original price
- •When comparing changes, always check whether percentages use the same base
- •Compound percentages multiply, not add - a 10% increase followed by another 10% is 21% total, not 20%
- •For quick mental math: 10% = divide by 10, 1% = divide by 100
- •Check if percentages exceed 100% - useful for detecting errors in data entry