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Percentage Calculator

Free percentage calculator supporting three calculation types: what percent is X of Y, what is X% of Y, and percentage increase/decrease. Choose your calculation type and get instant results.

Frequently Asked Questions

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

Divide the part by the total and multiply by 100. For example, if the part is 20 and the total is 80, the calculation is (20 ÷ 80) × 100 = 25%.

How do you calculate what is a percentage of a number?

Multiply the percentage by the number and divide by 100. For example, 20% of 100 is (20 × 100) ÷ 100 = 20.

How do you calculate percentage increase or decrease?

Use the formula: ((new value - old value) ÷ old value) × 100. A positive result is an increase, negative is a decrease.

Can the total be zero?

No, the total cannot be zero because division by zero is mathematically undefined. The calculator will show an error message if you try to use zero as the total.