Percentage Calculator
Three percentage calculators in one: find a percent of a number, find what percent one number is of another, and calculate percentage change.
20% of 80 is 16
How to use this calculator
Pick a mode at the top: X% of Y to find a percentage of a number, X is what % of Y to find a ratio as a percent, or % change to measure an increase or decrease between two values. Enter the two numbers and the answer appears instantly with a plain-English sentence.
How percentages work
A percentage is a fraction out of 100. To take a percent of a number, multiply by the percent ÷ 100. To express one number as a percent of another, divide and multiply by 100. Percentage change compares the difference against the original value.
Worked examples
20% of 80 = 16 · 20 is 25% of 80 · From 80 to 100 is a 25% increase · From 100 to 80 is a 20% decrease.
The formulas
Percent of: (X ÷ 100) × Y · Is what percent: (X ÷ Y) × 100 · Change: ((New − Old) ÷ Old) × 100
Frequently asked questions
How do I find a percentage of a number?
Convert the percentage to a decimal and multiply. 20% of 80 is 0.20 × 80 = 16. Use the 'X% of Y' mode above.
How do I find what percent one number is of another?
Divide the part by the whole and multiply by 100. 20 out of 80 is (20 ÷ 80) × 100 = 25%. Use the 'X is what % of Y' mode.
How do I calculate percentage increase or decrease?
Subtract the old value from the new value, divide by the old value, and multiply by 100. From 80 to 100 is ((100 − 80) ÷ 80) × 100 = 25% increase. A negative result means a decrease.
What's the difference between percentage points and percent?
A change from 10% to 15% is a 5 percentage-point rise but a 50% increase. Percentage points compare the rates directly; percent compares the relative change.