MyCalculatorHow this calculator works
% of a number: multiplies the number by the percentage and divides by 100. Formula: result = (percentage × number) ÷ 100.
X is what % of Y: divides the part by the whole and multiplies by 100. Formula: result = (X ÷ Y) × 100.
% increase / decrease: finds the difference between two values relative to the original. Formula: result = ((new − old) ÷ old) × 100. A positive result is an increase; a negative result is a decrease.
Example
What is 20% of 150? Using the formula: (150 × 20) ÷ 100 = 30. If a value rises from 150 to 180, the percentage increase is ((180 − 150) ÷ 150) × 100 = 20%.
Limitations
This tool performs pure arithmetic and does not account for currency, tax or rounding rules specific to any country. For salary or tax percentages, see our country-specific calculators.
Frequently asked questions
How do I calculate a percentage of a number?
Multiply the number by the percentage, then divide by 100. For example, 20% of 150 is (150 × 20) ÷ 100 = 30.
How do I find what percent one number is of another?
Divide the part by the whole and multiply by 100. For example, 30 out of 150 is (30 ÷ 150) × 100 = 20%.
How is percentage change calculated?
Subtract the old value from the new value, divide by the old value, and multiply by 100. A positive result is an increase; a negative result is a decrease.