Percentage Calculator

What is X% of a number? What percent is A of B? Free and widely used.

20
25%
Quick demo: how to use this tool
  1. Choose the type of calculation (percentage of a number, discount, increase, etc.).
  2. Fill in the requested fields.
  3. Press calculate and copy the result if you need it.

↑ Try the tool in the form above

About Percentage Calculator

Calculate percentages: what is X% of Y, what percentage is A of B, percentage increase or decrease. Fast and free. Percentage Calculator is a free tool from the Mathematics and Statistics category of RoviDev. Solve the calculation step by step so you can save time and check your results instantly. Perfect for studying, reviewing and verifying exercises.

How to use Percentage Calculator

  1. Open Percentage Calculator in RoviDev (you don't need to install anything or register).
  2. Enter the required data in the tool form.
  3. Press the button and see the result instantly on the screen.

Frequently asked questions

How is the percentage of a quantity calculated?

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

How do I calculate the percentage increase or discount?

Subtract the initial value from the final value, divide by the initial value and multiply by 100. If you go from 80 to 100, the increase is (100−80)/80 × 100 = 25%.

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

Divide the number by the total and multiply by 100. For example, 30 of 150 is 30/150 × 100 = 20%.

Can I calculate the inverse percentage?

Yes. If you know that 30 is 20%, the total is 30 × 100 / 20 = 150.