Choose the percentage question that matches yours, then enter the two requested values. Separate choices keep change and difference from being mixed together.
Choose the percentage relationship first
The numbers alone do not determine the formula. Identify whether you know a part and a whole, or whether you are comparing an old value with a new one, before entering anything.
Choose the question with the same unknown as yours. The form then shows only the two values you need to enter.
A part and whole must describe the same unit, such as dollars and dollars or points and points.
change always divides by the positive old value. difference treats two non-negative values equally.
Example: 25% of 120
- Choose What is 25% of 120?, enter 25 for Percentage and 120 for Number.
- The engine computes
25 ÷ 100 × 120 = 30, so 25% of 120 is 30.
Why each question has different fields
Each solve direction asks for a different unknown. Finding an amount needs Percentage and Number. Finding a percentage needs Amount and Total. Finding the total needs Amount and Percentage. The answer stays in the result area instead of becoming another editable field.
Percent change and percent difference are not interchangeable
From 80 to 100, change is (100 − 80) ÷ 80 × 100 = 25%. difference between 80 and 100 is 20 ÷ 90 × 100 = 22.22% because 90 is their average. The first answer describes movement from a baseline; the describes separation between peers.
Frequently asked questions
What does of a number mean?
It asks for a part of a whole at a rate per hundred. For example, 25% of 120 is 25 ÷ 100 × 120, which equals 30.
How do I calculate a percentage increase?
Subtract the old value from the new value, divide by the old value, and multiply by 100. A positive answer is an increase; a negative answer is a decrease.
When should I use difference instead of change?
Use difference for two peer measurements with no natural starting value. Use change when one value is the old or baseline value and the other is the new value.