How do I calculate X% of a number?

Multiply the number by the percentage divided by 100. For example, 20% of 150 = 150 × (20/100) = 150 × 0.2 = 30. This is useful for calculating discounts, taxes, or tips.

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

Divide the first number by the second, then multiply by 100. For example, to find what percent 30 is of 150: (30 / 150) × 100 = 20%. This shows that 30 is 20% of 150.

What's the difference between percentage increase and decrease?

Percentage increase measures how much a value grew: ((new - old) / old) × 100. Percentage decrease measures how much it shrunk: ((old - new) / old) × 100. Both use the original value as the base.

How do I calculate percentage change?

Use the formula: ((new value - old value) / old value) × 100. A positive result indicates an increase, negative indicates a decrease. For example, from 80 to 100: ((100-80)/80) × 100 = 25% increase.

Can percentages be greater than 100%?

Yes. Percentages over 100% mean the value is more than the whole. For example, if you had $100 and now have $250, that's a 150% increase. The new value is 250% of the original.

Is my calculation data sent to a server?

No. All calculations happen entirely in your browser using JavaScript. Your numbers and results are never transmitted over the network. The tool works offline after the page loads.

Tools

Percentage (%)

Number

Result

30.00

20% of 150 = (20 / 100) × 150 = 30

Percentage Calculator — Calculate Increase, Decrease & Ratio

Free percentage calculator for all percentage calculations. Calculate percentage increase, decrease, ratio, and change rate. Find what percent one number is of another. All calculations run locally in your browser.

Features

✓Calculate X% of a number (e.g., 20% of 150)
✓Find what percent one number is of another
✓Calculate percentage increase between two numbers
✓Calculate percentage decrease between two numbers
✓Calculate percentage change (increase or decrease)
✓Instant calculation as you type
✓Clear formula display showing the calculation
✓Support for negative percentages
✓Perfect for discounts, taxes, and statistics
✓All calculations run locally in your browser

How to Use

1Select the calculation type you need.
2Enter the first value (percentage or number).
3Enter the second value (number or percentage).
4View instant results with the formula.
5Switch between different calculation types as needed.

Frequently Asked Questions

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