Percentage Calculator
Calculate X% of Y, what percent X is of Y, percentage increase/decrease, or percentage difference — with the formula and substitution shown.
Calculated entirely in your browser — nothing you enter here is sent to a server.
Percentage increase/decrease and percentage difference are often confused but answer different questions. Increase/decrease compares a new value back to a specific starting point (order matters: going from 50 to 75 is a 50% increase, but going from 75 back to 50 is a 33.3% decrease, not 50%). Percentage difference instead compares two values to each other with no notion of which came first, using their average as the base.
A percentage change from a starting value of zero, or a percentage of zero, is mathematically undefined — this calculator reports that clearly instead of showing a meaningless Infinity or NaN.