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Percentage calculator step by step

Calculate percentages instantly: how much is X% of a number, or what percentage one quantity represents of another. With step-by-step working.

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How how to calculate percentages

To find X% of a number N: result = N · X / 100. To find what percentage A is of B: percentage = (A / B) · 100.

A percentage is simply a proportion over 100 (a rule of three).

ExampleWhat is 20% of 150?

Step-by-step solution

  1. Formula: N · X / 100 = 150 · 20 / 100.
  2. We calculate: 3000 / 100 = 30.
Result: 20% of 150 is 30.

Don't just focus on the result: learn how to do it

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Frequently asked questions

How do you calculate the percentage of a number?

Multiply the number by the percentage and divide by 100. For example, 20% of 150 is 150 · 20 / 100 = 30.

How do you know what percentage one number is of another?

Divide the part by the total and multiply by 100. For example, 30 out of 150 is (30 / 150) · 100 = 20%.

Is the calculator free?

Yes, the percentages calculator is free. And if you want to practice with hundreds of instantly corrected exercises, you have a 5-day trial with no card required on Refuerzo.ai.