How do I calculate a percentage?

To find X% of Y, multiply Y by X and divide by 100. For example, 20% of 150 = 150 × 20 ÷ 100 = 30.

How do I calculate percentage change?

Subtract the old value from the new value, divide by the old value, and multiply by 100. A positive result is an increase; negative is a decrease.

Percentage Calculator | The Life Calculators

Percentage Calculator

Percentage (%)

Value Y

Result

50.00

How This Calculation Works

This calculator handles three types of percentage problems: "What is X% of Y?" (multiply Y by X/100), "X is what % of Y?" (divide X by Y and multiply by 100), and "% change from A to B" ((B−A)/A × 100).

Common Mistakes to Avoid

Confusing percentage of vs percentage change. 25% of 200 is 50, but a change from 200 to 250 is a 25% increase.
Percentage points vs percent. Going from 10% to 15% is a 5 percentage point increase, but a 50% relative increase.

Worked Example

What is 15% of 80? 80 × 15/100 = 12.

30 is what % of 120? 30 ÷ 120 × 100 = 25%.

% change from 50 to 75? (75−50) ÷ 50 × 100 = 50% increase.

Frequently Asked Questions

How do I calculate a percentage?: To find X% of Y, multiply Y by X and divide by 100. For example, 20% of 150 = 150 × 20 ÷ 100 = 30.
How do I calculate percentage change?: Subtract the old value from the new value, divide by the old value, and multiply by 100. A positive result is an increase; negative is a decrease.

Percentage Calculator