Percentage Calculator
Work out a percentage of a number, what percent one number is of another, or the percent change between two values.
Three of the most common percentage questions in one place: discounts and tips, scores and shares, and increases or decreases over time. Each answer comes with a plain English sentence so you can check the logic.
Pick a mode, enter two numbers and press Calculate.
How to use this tool
Choose a calculation mode, enter the two values, then press Calculate. Switching modes changes the meaning of X and Y, which is explained in the result.
Example use case
A shopper checks the sale price of a 65 dollar jacket at 30 percent off, then uses percent change to compare it with last season.
Limitations and accuracy notes
Results are rounded to two decimal places for display. Sales tax, shipping and rounding rules used by individual stores are not included.
Frequently asked questions
How is percent change calculated?
New value minus old value, divided by the absolute old value, times 100.
Why can Y not be zero?
Dividing by zero is undefined, so the calculation cannot run.
Does it handle negative numbers?
Yes, percent change supports negative starting values.
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