Three of the most common percentage questions in one tool: a percentage of a number, what share one number is of another, and percentage change.
Percentage questions all reduce to the same handful of relationships, but it's easy to plug numbers into the wrong one. This calculator labels the fields for whichever mode you pick so you always know what's being divided by what.
Percentage change is always measured against the starting value, not the ending one. Going from 50 to 75 is a 50% increase, but going from 75 back down to 50 is only a 33.3% decrease — the same two numbers give different percentages depending on direction, which trips people up when comparing "before and after" figures.
A change from 20% to 25% is a 5 percentage-point increase, but a 25% relative increase in the rate itself. The two describe different things and shouldn't be used interchangeably.
Yes — if Y is smaller than X, the percentage change mode returns a negative number, correctly showing a decrease.
Use 'X% of a number' to find the increase amount, then add it to the original number yourself, or use 'percentage change' mode if you already know both the before and after figures.