Percentage Calculator
Four common percentage problems on one page, each with a one-line explanation.
What is P% of X?
% of
Result: 25
20% of 125 is 25 because 20 ÷ 100 × 125 = 25
X is what % of Y?
of
20%
25 is 20% of 125 because 25 ÷ 125 × 100 = 20
Percent change
→
25%
From 80 to 100 is a 25% increase because (100 − 80) ÷ 80 × 100 = 25
X is P% of what?
is%
Whole: 125
25 is 20% of 125 because 25 ÷ 20 × 100 = 125
How it works
P% of X = P ÷ 100 × X. “X is what % of Y” = X ÷ Y × 100. Percent change = (new − old) ÷ |old| × 100.
Results round to two decimal places for readability.