Percentage Calculator

How to Use the Percentage Calculator

Our percentage calculator offers five different calculation modes to handle all your percentage needs:

1. What is X% of Y?

This mode calculates what a certain percentage of a number equals. For example, "What is 20% of 100?" The answer is 20.

Use cases: Calculating tips, discounts, tax amounts, commission rates

2. X is what % of Y?

Find out what percentage one number represents of another. For example, "25 is what % of 100?" The answer is 25%.

Use cases: Test scores, completion rates, market share analysis

3. Percentage Change

Calculate the percentage increase or decrease from one value to another. Shows both the percentage change and absolute difference.

Use cases: Stock market changes, sales growth, weight loss tracking

4. Percentage Increase

Increase a number by a specific percentage. For example, increasing 100 by 10% gives you 110.

Use cases: Salary increases, price markups, investment growth

5. Percentage Decrease

Decrease a number by a specific percentage. For example, decreasing 100 by 25% gives you 75.

Use cases: Discounts, depreciation, budget cuts

Percentage Formulas Explained

Basic Percentage Formula

Percentage = (Part ÷ Whole) × 100

Percentage of a Number

Result = (Percentage ÷ 100) × Number

Percentage Change

% Change = [(New Value - Old Value) ÷ Old Value] × 100

Percentage Increase

New Value = Original × (1 + Percentage ÷ 100)

Percentage Decrease

New Value = Original × (1 - Percentage ÷ 100)

Common Percentage Calculations

Calculating Tips

To calculate a 15% tip on a $50 bill: (15 ÷ 100) × 50 = $7.50

Sales Discounts

A $100 item with 25% off: 100 × (1 - 25 ÷ 100) = $75

Test Scores

If you got 45 out of 50 questions correct: (45 ÷ 50) × 100 = 90%

Tax Calculations

Adding 8% sales tax to $200: 200 × (1 + 8 ÷ 100) = $216

Investment Returns

If an investment grows from $1,000 to $1,200: [(1,200 - 1,000) ÷ 1,000] × 100 = 20% return

Percentage Tips and Tricks

• Finding 10%: Just move the decimal point one place to the left (10% of 85 = 8.5)
• Finding 5%: Calculate 10% and divide by 2
• Finding 1%: Divide the number by 100
• Finding 50%: Simply divide by 2
• Finding 25%: Divide by 4
• Finding 20%: Divide by 5
• Quick tip calculation: For 15%, find 10% and add half of that amount

Real-World Applications

Finance & Business

• Calculate interest rates and returns
• Determine profit margins
• Analyze sales growth
• Compare financial performance

Shopping & Retail

• Calculate discounts and sale prices
• Determine tip amounts
• Figure out tax on purchases
• Compare price changes

Education

• Calculate test scores and grades
• Determine GPA percentages
• Track academic improvement
• Analyze class performance

Health & Fitness

• Track weight loss/gain percentages
• Calculate body fat changes
• Monitor fitness improvements
• Analyze nutritional values

Frequently Asked Questions

How do you calculate a percentage of a number?

To find a percentage of a number, divide the percentage by 100 and multiply by the number. For example, 25% of 80 = (25 ÷ 100) × 80 = 20.

What is the difference between percentage increase and decrease?

A percentage increase adds value to the original number, while a percentage decrease subtracts value. Both are calculated based on the original amount.

How do you convert a fraction to a percentage?

Divide the numerator by the denominator and multiply by 100. For example, 3/4 = 0.75 × 100 = 75%.

Can a percentage be more than 100%?

Yes! Percentages can exceed 100%. For example, if something doubles in value, that's a 100% increase, and tripling is a 200% increase.

What is the percentage change from 50 to 75?

[(75 - 50) ÷ 50] × 100 = 50% increase.

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