Percentage Calculator

Calculate percentages, percentage increase/decrease, and find what percentage one number is of another.

Formula: (Percentage ÷ 100) × Value
What is % of ?
Formula: (Part ÷ Whole) × 100
is what % of ?
Formula: ((New - Old) ÷ Old) × 100
From to
Free Online Percentage Calculator

This percentage calculator helps you quickly solve common percentage problems. Calculate what percentage one number is of another, find a percentage of a value, or determine percentage increase or decrease.

Perfect for shopping discounts, tax calculations, grade calculations, and financial planning. All calculations happen instantly in your browser.

Step-by-Step Calculation Examples

Example 1: Finding 35% of 280 - Using the "What is X% of Y?" calculator: Enter 35 in the first field and 280 in the second field. The result is 98. This means 35% of 280 equals 98.

Example 2: What percentage is 45 out of 180? - Using the "X is what % of Y?" calculator: Enter 45 and 180. The result is 25%. So 45 is 25% of 180.

Example 3: Calculating price increase from $120 to $156 - Using the "% Increase/Decrease" calculator: Enter 120 as the old value and 156 as the new value. The result shows a 30% increase.

Real-World Applications

Shopping & Discounts: Calculate sale prices instantly. If an item costs $80 with 25% off, you save $20. Use the "What is X% of Y?" calculator to find the discount amount, then subtract from the original price.

Academic Grading: Determine what percentage you scored on a test. If you got 85 points out of 100 possible, that's (85 ÷ 100) × 100 = 85%.

Financial Planning: Calculate tax amounts, tip percentages, and investment returns. A 15% tip on a $60 meal is (15 ÷ 100) × 60 = $9.

Percentage Formulas Explained

Finding a Percentage of a Number: The formula (Percentage ÷ 100) × Value works for any percentage calculation. To find 30% of 200: (30 ÷ 100) × 200 = 60.

Percentage of a Whole: The formula (Part ÷ Whole) × 100 expresses one number as a percentage of another. If 40 students passed out of 50 total, the pass rate is (40 ÷ 50) × 100 = 80%.

Percentage Change: The formula ((New - Old) ÷ Old) × 100 measures growth or decline. A price drop from $200 to $160 is a 20% decrease: ((160 - 200) ÷ 200) × 100 = -20%.

How to Use

Choose from four modes: find X% of a number, find what percent A is of B, calculate percentage increase/decrease, or find the original number from a percentage. Enter your values and see the result instantly. Results show the formula used for clarity.

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 divided by 100. For example, to find 20% of 100, calculate (20 ÷ 100) × 100 = 20.

How do I find what percentage one number is of another?

Divide the first number (the part) by the second number (the whole), then multiply by 100. For example, 25 is 25% of 100 because (25 ÷ 100) × 100 = 25.

How do I calculate percentage increase or decrease?

Subtract the original value from the new value, divide by the original value, then multiply by 100. For example, going from 100 to 150 is a 50% increase because ((150 - 100) ÷ 100) × 100 = 50.

Is this percentage calculator free to use?

Yes, this percentage calculator is completely free. No registration or signup is required.

Can I use this for calculating discounts?

Absolutely. To calculate a discounted price, use the "What is X% of Y?" calculator to find the discount amount, then subtract it from the original price.

Are my calculations saved or stored anywhere?

No. All calculations happen entirely in your browser. No data is sent to any server or stored anywhere.

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