IWantFreeTools.com Free tools that just work.

Percentage Calculator

Find percentages, work out what percent one number is of another, or calculate percentage change. Results appear instantly as you type.

%
Result
--
Enter numbers above to see the result
Result
--
Enter numbers above to see the result
% Change
--
Enter numbers above to see the result

How to Use the Percentage Calculator

1
Pick the right tab. "X% of Y" for discounts or tips. "X is what % of Y" for grades or ratios. "% Change" for price or growth changes.
2
Enter your numbers. Type into any field and the result appears instantly, no button press needed.
3
Copy the result. Click "Copy Result" to copy the full answer text to your clipboard.

Percentage Formulas

What is X% of Y?

Result = (X / 100) x Y

X is what % of Y?

Result = (X / Y) x 100

Percentage change from A to B:

Change = ((B - A) / |A|) x 100

A positive result means an increase; a negative result means a decrease.

Related Tools

🏷️ Discount Calculator Find sale price and total savings Use tool → 🍽️ Tip Calculator Calculate tip and split the bill Use tool → ⚖️ BMI Calculator Calculate your Body Mass Index Use tool →

Frequently Asked Questions

How do I calculate percentage?

To find X% of a number Y, multiply Y by X and divide by 100. For example: 15% of 200 = 200 x 15 / 100 = 30. Or simply multiply by the decimal: 200 x 0.15 = 30.

How do I find what percentage X is of Y?

Divide X by Y and multiply the result by 100. Example: 30 is what % of 200? Answer: (30 / 200) x 100 = 15%. This is useful for grades, test scores, and progress tracking.

How do I calculate percentage increase?

Subtract the old value from the new value, divide by the old value, then multiply by 100. Example: from 80 to 100 = ((100 - 80) / 80) x 100 = 25% increase. Use the "% Change" tab above for this.

What is 20% of 100?

20% of 100 is 20. Calculation: 100 x (20 / 100) = 100 x 0.20 = 20. You can verify this instantly using Tab 1 above by entering 20 and 100.

How do I calculate a percentage decrease?

Use the same formula as percentage increase. If the result is negative, it is a decrease. Example: from 100 to 80 = ((80 - 100) / 100) x 100 = -20%, meaning a 20% decrease. The calculator shows "decrease" automatically in red.