Percentage calculator
Three ways to ask the same kind of question. Type numbers, get the answer and the formula that produced it.
X% of Y
12
X is what percent of Y
25%
Percent change
+30%
Frequently asked questions
How do I calculate X percent of a number?
Multiply the number by the percentage and divide by 100. For example, 15% of 80 is 80 x 15 / 100 = 12.
How do I work out what percent one number is of another?
Divide the part by the whole and multiply by 100. If 30 of 120 students passed, that is 30 / 120 x 100 = 25%.
How is percent change calculated?
Subtract the old value from the new value, divide by the old value, then multiply by 100. Going from 50 to 65 is (65 - 50) / 50 x 100 = a 30% increase. A negative result means a decrease.
Why is a 50% increase then a 50% decrease not back to the start?
Because the second percentage applies to a bigger base. 100 up 50% is 150; 150 down 50% is 75. Percent changes compound on the current value, not the original.