Percentage Calculator
Calculate percentages for any situation. Find percentage of a number, calculate percentage increase or decrease, determine what percentage one number is of another, and calculate percentage change between two values. Perfect for shopping discounts, tips, taxes, grades, finance, and statistics.
How It Works
1. Choose Calculation Type
Select what you want to calculate: percentage of a number, what percentage one number is of another, increase/decrease by percentage, or percentage change between values.
2. Enter Your Numbers
Input the values based on your selected calculation type. The calculator provides clear labels and examples for each type.
3. Get Instant Results
Click Calculate to see your answer with a full explanation of the calculation. Includes the formula used and practical examples.
4. Use the Formula Guide
Reference the quick formulas and common use cases to understand how percentages work and apply them to real-world situations.
Examples
Example 1: Shopping Discount
Question: A $80 jacket is 25% off. What is the discount and final price? Calculation Type: What is X% of Y? Percentage: 25% Of Number: 80 Result: $20 Discount: $20 Final Price: $80 - $20 = $60 You save $20 on a 25% discount.
Example 2: Restaurant Tip
Question: Your bill is $45.50. You want to leave 18% tip. How much? Calculation Type: What is X% of Y? Percentage: 18% Of Number: 45.50 Result: $8.19 Total with Tip: $45.50 + $8.19 = $53.69 Leave $8.19 tip (or round to $8-9).
Example 3: Test Score
Question: You got 42 out of 50 on a test. What's your percentage? Calculation Type: X is what % of Y? Part Number: 42 Total Number: 50 Result: 84% Your test score is 84%.
Example 4: Salary Increase
Question: Your salary is $50,000. You get a 7% raise. What's your new salary? Calculation Type: Increase by % Original Value: 50000 Percentage: 7% Type: Increase Result: $53,500 Increase Amount: $3,500 Your new salary is $53,500 (up $3,500).
Example 5: Stock Price Change
Question: A stock went from $120 to $150. What's the % change? Calculation Type: Percentage Change Old Value: 120 New Value: 150 Result: 25% increase Change: +$30 The stock increased by 25%.
Frequently Asked Questions
How do I calculate a percentage of a number?
To find a percentage of a number, divide the percentage by 100 and multiply by the number. Formula: (Percentage ÷ 100) × Number. For example, 20% of 100 = (20 ÷ 100) × 100 = 0.2 × 100 = 20. Quick tip: To find 10%, just move the decimal point left one place (10% of 80 = 8).
What is the difference between percentage increase and percentage change?
Percentage increase adds a percentage to a starting value (e.g., increase $100 by 20% = $120). Percentage change measures the change between two values as a percentage (e.g., from $100 to $120 is a 20% increase). Use increase/decrease when you know the starting value and percentage. Use percentage change when you have two values and want to find the percentage difference.
How do I calculate percentage decrease (discount)?
For a percentage decrease, multiply the original value by the percentage and subtract from the original. Formula: Original × (1 - Percentage/100). For example, 30% off $50: $50 × (1 - 30/100) = $50 × 0.7 = $35. Or calculate the discount amount: 30% of $50 = $15, then $50 - $15 = $35.
How do I find what percentage one number is of another?
Divide the part by the total and multiply by 100. Formula: (Part ÷ Total) × 100. For example, what percent is 15 of 60? (15 ÷ 60) × 100 = 0.25 × 100 = 25%. This is useful for test scores, completion rates, or comparing portions to totals.
Why does a 50% increase followed by a 50% decrease not return to the original value?
Because percentages are relative to the current value, not the original. Example: Start with 100. Increase by 50% → 150. Then decrease 150 by 50% → 75 (not 100). The 50% decrease applies to 150, not 100. To return to the original after a 50% increase, you need a 33.33% decrease (because 150 × 0.6667 = 100).