Percentage Calculator
Free online percentage calculator. Calculate percentages, percentage change, increase, decrease, and more. Fast, accurate, and easy to use with explanations.
What is X% of Y?
Calculate any simple percentage portion of a number
About the Percentage Calculator
Our free online percentage calculator is a comprehensive tool designed to handle all your percentage calculation needs. Whether you need to calculate basic percentages, percentage changes, increases, decreases, or find what percentage one number is of another, our calculator provides instant, accurate results with detailed explanations.
Percentages are fundamental in mathematics, finance, statistics, and everyday life. From calculating discounts and tax rates to analyzing business growth and academic grades, understanding percentages is essential. Our calculator makes these calculations simple and error-free, saving you time and ensuring accuracy.
Calculator Modes
1. What is X% of Y? (Basic Percentage)
This mode calculates what a given percentage of a number equals. Perfect for finding discounts, tips, tax amounts, or any situation where you need to find a portion of a whole.
Formula: (Percentage ÷ 100) × Number = Result
Example: What is 25% of 200? → (25 ÷ 100) × 200 = 50
Common Uses: Calculating sales discounts, finding tip amounts, determining tax on purchases, calculating commission rates, finding interest amounts.
2. Percentage Change Calculator
Calculate the percentage increase or decrease between two values. This is essential for analyzing growth rates, price changes, population changes, or any comparison between an old and new value.
Formula: ((New Value - Original Value) ÷ Original Value) × 100 = Percentage Change
Example: From 100 to 150 → ((150 - 100) ÷ 100) × 100 = +50% (increase)
Common Uses: Stock price changes, salary increases, business growth analysis, population growth, sales performance tracking, year-over-year comparisons.
3. Percentage Increase Calculator
Increase a number by a specific percentage. Useful for calculating price increases, salary raises, inflation adjustments, or projecting future values.
Formula: Number + (Number × (Percentage ÷ 100)) = Result
Example: Increase 100 by 20% → 100 + (100 × 0.20) = 120
Common Uses: Calculating price after markup, determining salary after raise, projecting growth, adding tax to prices, calculating compound interest.
4. Percentage Decrease Calculator
Decrease a number by a specific percentage. Perfect for calculating discounts, depreciation, budget cuts, or any reduction scenarios.
Formula: Number - (Number × (Percentage ÷ 100)) = Result
Example: Decrease 100 by 20% → 100 - (100 × 0.20) = 80
Common Uses: Calculating sale prices, determining discounted amounts, calculating depreciation, budget reductions, weight loss percentages.
5. X is What % of Y? (Percentage Difference)
Find what percentage one number represents of another. Ideal for calculating completion rates, success rates, or determining proportions.
Formula: (Part ÷ Whole) × 100 = Percentage
Example: 50 is what % of 200? → (50 ÷ 200) × 100 = 25%
Common Uses: Calculating test scores, determining completion rates, finding market share, calculating conversion rates, analyzing survey results.
Real-World Applications
Shopping & Retail
- Discounts: Calculate the final price after a percentage discount (e.g., 30% off $100 = $70)
- Sales Tax: Add sales tax to a purchase price (e.g., $100 + 8% tax = $108)
- Tips: Calculate appropriate tip amounts at restaurants (e.g., 20% of $50 = $10)
- Price Comparisons: Compare prices and savings across different stores
Finance & Business
- Interest Rates: Calculate interest on loans, savings, or investments
- Profit Margins: Determine profit as a percentage of revenue
- Growth Rates: Analyze business growth year-over-year
- Commission: Calculate sales commission based on percentage rates
- ROI: Calculate return on investment percentages
Education & Academics
- Test Scores: Convert raw scores to percentages (e.g., 45/50 = 90%)
- Grade Calculations: Calculate weighted grades and final scores
- GPA: Convert percentage grades to GPA scales
- Improvement Tracking: Measure academic progress over time
Health & Fitness
- Weight Loss: Track weight loss as a percentage of starting weight
- Nutrition: Calculate daily value percentages for nutrients
- Progress Tracking: Measure fitness improvements over time
- Heart Rate Zones: Calculate target heart rate percentages
Statistics & Data Analysis
- Survey Results: Express survey responses as percentages
- Market Share: Calculate company market share percentages
- Conversion Rates: Measure website or sales conversion rates
- Demographics: Analyze population distributions
How to Calculate Percentages Manually
Method 1: Finding a Percentage of a Number
- Convert the percentage to a decimal by dividing by 100
- Multiply the decimal by the number
- Example: 25% of 80 → 0.25 × 80 = 20
Method 2: Finding What Percentage One Number Is of Another
- Divide the part by the whole
- Multiply the result by 100
- Example: 20 is what % of 80? → (20 ÷ 80) × 100 = 25%
Method 3: Calculating Percentage Change
- Subtract the original value from the new value
- Divide the difference by the original value
- Multiply by 100
- Example: From 50 to 75 → ((75 - 50) ÷ 50) × 100 = 50% increase
Common Percentage Conversions
Tips for Working with Percentages
- Double-Check Your Work: When calculating manually, verify your results with our calculator to ensure accuracy.
- Understand the Context: Make sure you know whether you're calculating an increase, decrease, or simple percentage.
- Watch for Order: In percentage change calculations, the order matters - changing from 50 to 100 is different from 100 to 50.
- Use Decimal Places: For precision, keep at least 2 decimal places in your calculations.
- Percentage vs. Percentage Points: A change from 10% to 20% is a 10 percentage point increase, but a 100% relative increase.
- Compound Percentages: Multiple percentage changes don't simply add up - a 10% increase followed by a 10% decrease doesn't return to the original value.
Frequently Asked Questions
How do I calculate a percentage?
To calculate a percentage, divide the part by the whole and multiply by 100. For example, to find what percentage 25 is of 100: (25 ÷ 100) × 100 = 25%. Our percentage calculator does this automatically for you.
How do I calculate percentage change?
To calculate percentage change, subtract the original value from the new value, divide by the original value, and multiply by 100. Formula: ((New Value - Original Value) / Original Value) × 100. A positive result indicates an increase, while a negative result indicates a decrease.
How do I calculate percentage increase?
To calculate percentage increase, find the difference between the new and original values, divide by the original value, and multiply by 100. For example, if a value increases from 100 to 120: ((120 - 100) / 100) × 100 = 20% increase.
How do I calculate percentage decrease?
Percentage decrease is calculated the same way as percentage increase, but the result will be negative. Alternatively, subtract the new value from the original, divide by the original, and multiply by 100. For example, from 100 to 80: ((100 - 80) / 100) × 100 = 20% decrease.
What is the difference between percentage and percentile?
A percentage is a fraction expressed as a part of 100 (e.g., 25% = 25/100). A percentile is a measure used in statistics indicating the value below which a given percentage of observations fall. For example, being in the 90th percentile means you scored better than 90% of others.
How do I convert a fraction to a percentage?
To convert a fraction to a percentage, divide the numerator by the denominator and multiply by 100. For example, 3/4 = 0.75 × 100 = 75%. You can also use our calculator by entering the numerator as the "part" and denominator as the "whole" in the "X is what % of Y?" mode.
How do I convert a decimal to a percentage?
To convert a decimal to a percentage, simply multiply by 100 and add the % symbol. For example, 0.75 × 100 = 75%. Conversely, to convert a percentage to a decimal, divide by 100 (e.g., 75% ÷ 100 = 0.75).
Can percentages be greater than 100%?
Yes! Percentages can exceed 100%. This commonly occurs when calculating percentage increases. For example, if a stock price doubles from $50 to $100, that's a 100% increase. If it triples to $150, that's a 200% increase.
How do I calculate the percentage of a percentage?
To find a percentage of a percentage, convert both to decimals, multiply them, then convert back. For example, 20% of 50% = 0.20 × 0.50 = 0.10 = 10%. Or use our calculator twice: first find 50% of your number, then find 20% of that result.
What is the percentage formula?
The basic percentage formula is: (Part / Whole) × 100 = Percentage. For percentage change: ((New - Old) / Old) × 100. For finding a percentage of a number: (Percentage / 100) × Number. Our calculator handles all these formulas automatically.
Why Use Our Percentage Calculator?
- 100% Free: No registration, no hidden fees, unlimited calculations.
- Multiple Modes: Five different calculation modes to handle any percentage scenario.
- Instant Results: Get accurate answers immediately with detailed explanations.
- User-Friendly: Clean, intuitive interface that's easy to use on any device.
- Educational: Learn the formulas and understand how percentages work.
- No Installation: Works directly in your browser, no downloads required.
- Mobile-Friendly: Fully responsive design works perfectly on phones and tablets.
- Privacy-Focused: All calculations happen in your browser - we don't store your data.