Percentage Calculator

Calculate percentages in seconds, with the working shown

What isof?

How to use the calculator

This calculator covers the four percentage problems that come up most often: what a percentage of a number is, what percentage one number is of another, what a value becomes after an increase, and what it becomes after a discount. Fill in the sentence and the result updates as you type.

Example: to find 15% of 200, pick "What is X% of Y?", enter 15 and 200, and the answer (30) appears immediately.

Step-by-Step:

  1. Start with the percentage: 15%
  2. Convert to decimal by dividing by 100: 15 ÷ 100 = 0.15
  3. Multiply by the value: 0.15 × 200 = 30

To find 15% of 200, we convert the percentage to a decimal and multiply. Think of it as "parts per hundred" - 15 out of every 100, applied to 200.

Frequently asked questions

How do you calculate a percentage of a number?

Divide the percentage by 100, then multiply by the number. For 15% of 200: 15 ÷ 100 = 0.15, then 0.15 × 200 = 30.

Is this calculator free?

Yes. It is free, requires no signup, and every calculation runs in your own browser, so nothing is sent to a server.

Does it work on mobile and offline?

Yes. It runs in any browser and can be installed as an app. After the first visit it keeps working without a connection.