Percentage Calculator

How do you calculate a percentage?

Divide the percentage by 100 and multiply by the number. For example, 25% of 200 is 0.25 × 200 = 50. This is the most common percentage calculation and the calculator handles it automatically as you type.

Finding what percentage one number is of another

Divide the first number by the second and multiply by 100. So 30 out of 150 is (30 ÷ 150) × 100 = 20%. Switch to the “X is what % of Y” mode to calculate this.

Percentage change

Subtract the old value from the new value, divide by the old value, and multiply by 100. A change from 80 to 100 is ((100 − 80) ÷ 80) × 100 = 25% increase. If the result is negative, the value has decreased.