Percentage Calculator

What is X% of Y?

Calculate a percentage of any number. Perfect for tips, discounts, and proportions.

Percentage *

% of

Value *

Common Percentage Calculations

How to Use the Percentage Calculator

Choose Your Calculation Type

X% of Y - Find a percentage of a number (tips, discounts)
X is what % of Y - Calculate percentage between two numbers
X is Y% of what - Find the original value
% Increase/Decrease - Calculate percentage change
Add/Subtract % - Apply percentage to a value

Quick Tips

Use the tabs above to switch between calculation types
Click the example buttons for common calculations
Results are calculated instantly as you type
Works with decimals for precise calculations

Real-World Use Cases

Shopping & Discounts

Calculate sale prices, discounts, and savings. If an item is 30% off the original $80 price, use "Subtract %" to find the sale price of $56, saving you $24.

Tips & Gratuity

Quickly calculate restaurant tips. For a 20% tip on a $75 dinner, use "X% of Y" to get $15. Add it to your bill or split among friends easily.

Grades & Test Scores

Convert raw scores to percentages. If you scored 42 out of 50 on a test, use "X is what % of Y" to find your grade is 84%.

About Our Percentage Calculator

Our free online percentage calculator is a versatile tool designed to handle all types of percentage calculations quickly and accurately. Whether you need to calculate a tip at a restaurant, figure out a discount during a sale, determine your test score percentage, or analyze percentage increases and decreases, this calculator has you covered.

Percentages are everywhere in daily life. From finance and shopping to academics and health, understanding how to calculate percentages is an essential skill. Our calculator eliminates the need for manual math, reducing errors and saving time. Simply select your calculation type, enter your values, and get instant results with clear explanations.

Understanding Percentage Calculations

At its core, a percentage represents a fraction of 100. The word comes from the Latin "per centum," meaning "by the hundred." When we say 25%, we mean 25 out of every 100, or 25/100, which equals 0.25 as a decimal. This relationship forms the basis of all percentage calculations.

The basic percentage formula is: Percentage = (Part ÷ Whole) × 100. For example, if you answered 18 questions correctly out of 24 on a quiz, your percentage would be (18 ÷ 24) × 100 = 75%. Our calculator applies this formula and its variations automatically, so you never have to remember which numbers go where.

Common Percentage Calculations Explained

Finding X% of Y: This is the most common percentage calculation. To find 15% of 200, multiply 200 by 0.15 (or 15/100) to get 30. Use this for calculating tips, taxes, commissions, and portions of any quantity.

Percentage Increase/Decrease: When comparing two values over time, the formula is: ((New Value - Old Value) ÷ Old Value) × 100. If a stock price went from $50 to $65, the increase is ((65 - 50) ÷ 50) × 100 = 30%. A negative result indicates a decrease.

Reverse Percentage: Sometimes you know the result and the percentage but need to find the original number. If an item costs $80 after a 20% discount, the original price was $80 ÷ 0.80 = $100. Our "X is Y% of what" calculator handles these reverse calculations.

Practical Applications

Financial Planning: Calculate interest rates, investment returns, mortgage percentages, and tax amounts. Understanding percentage changes helps you make informed financial decisions and compare different options accurately.

Business & Sales: Determine profit margins, calculate markups and discounts, analyze sales performance, and track growth rates. Businesses rely on percentage calculations for pricing strategies, performance metrics, and forecasting.

Health & Fitness: Track body fat percentage changes, calculate nutritional values, monitor weight loss progress, and determine caloric intake percentages. Percentages make it easy to measure progress over time regardless of absolute numbers.

Education: Convert raw test scores to percentages, calculate GPA contributions, determine passing thresholds, and compare performance across different assessments with varying total points.

Frequently Asked Questions

How do I calculate a percentage of a number?

To calculate a percentage of a number, multiply the number by the percentage and divide by 100. For example, to find 15% of 200: (200 × 15) ÷ 100 = 30. Our calculator does this instantly for you—just use the "X% of Y" tab.

How do I calculate percentage increase or decrease?

To calculate percentage change, subtract the old value from the new value, divide by the old value, and multiply by 100. Formula: ((New - Old) / Old) × 100. A positive result is an increase, negative is a decrease. Use our "% Increase/Decrease" tab for quick calculations.

What is the percentage formula?

The basic percentage formula is: Percentage = (Part / Whole) × 100. For example, if you scored 45 out of 60 on a test: (45 / 60) × 100 = 75%. This formula helps you find what percentage one number is of another.

How do I calculate a tip?

To calculate a tip, multiply your bill amount by the tip percentage and divide by 100. For a 20% tip on a $50 bill: (50 × 20) / 100 = $10 tip. Use the "X% of Y" calculator above for quick tip calculations—enter 20 for the percentage and your bill amount for the value.

How do I find the original price before a discount?

If you know the discounted price and the discount percentage, divide the sale price by (1 - discount/100). For example, if something costs $80 after a 20% discount: $80 / (1 - 0.20) = $80 / 0.80 = $100 original price. Use our "X is Y% of what" calculator—enter the sale price as X and (100 - discount%) as Y.

What is X% of Y?

X is what percent of Y?

X is Y% of what number?

Percentage Increase or Decrease

Add or Subtract a Percentage