Calculate percentages, percentage increase and decrease, and what percent one number is of another. Instant answers for discounts and grades.
Three questions get called “a percentage calculation” and they need three different equations. What is 15% of 80? 12 is what percent of 80? And what is the change from 80 to 92? The Percentage Calculator gives each its own mode, with the input labels rewriting themselves so you always know which number goes where.
Switching mode clears both fields on purpose. The numbers mean something different in each one, and carrying a “From value” over into a “Percentage” box is how you end up confidently reading a wrong answer.
Results carry up to 4 decimal places with trailing zeros stripped, so 25 stays 25 rather than becoming 25.0000, and a recurring value such as a third of 100 shows as 33.3333%. Everything is plain arithmetic on the page.
A subscription went from 80 to 92. Choose % Change, put 80 in From value and 92 in To value, and the answer is 15%. Now reverse it: 92 down to 80 is -13.0435%, not -15%. The base changed, and that asymmetry is the single most common percentage mistake in a business deck. Use X is what % of Y with 12 and 80 for the other framing, which gives 15% again because 12 is the size of the increase.
Cannot divide by zero instead of infinity.Cannot divide by zero. Growth from nothing has no percentage.