Power Calculators

% Percentage Calculator

Calculate a percentage of a number, find what percentage one number is of another, and find the whole when a percentage and part are known.

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Enter details

Enter the known value.
Enter the second value used by the selected calculation.

Fill in the details and click Calculate to see your results.


Also available in our Android app, with charts and full breakdown tables.

📘 About the Percentage

Percentage means a value expressed as a part of 100.

This calculator covers three common percentage questions: finding a percentage of a value, finding what percentage one value is of another, and finding the original whole from a part and percentage.

🧮 Formula

Percentage of a number
P% of B = P × B ÷ 100
Percentage of a whole
A as a percentage of B = A ÷ B × 100
Find the whole
Whole = A × 100 ÷ B

Where

  • A = first value
  • B = second value
  • P = percentage
Enter values according to the selected question.

✏️ Worked examples

15% of 240

You enter
First Value15
Second Value240
CalculationWhat is A% of B?
You get
Percentage Result36

The result is 36.

Try this example →

45 is what percent of 180?

You enter
First Value45
Second Value180
CalculationA is what % of B?
You get
Percentage Result25

The result is 25%.

Try this example →

🧭 How to use this calculator

What you enter

  • First ValueEnter the known value.
  • Second ValueEnter the second value used by the selected calculation.
  • Calculation

What you get

  • Percentage Result

💡 Common percentage uses

  • Discounts and price changes.
  • Marks and scores.
  • Population and statistical comparisons.
  • Business and financial calculations.

❓ Frequently asked questions

How do I calculate a percentage of a number?

Multiply the percentage by the number and divide by 100.

How do I find what percent A is of B?

Divide A by B and multiply by 100.

Can the calculator work with decimals?

Yes. Decimal inputs are accepted.