Percentage Change Calculator
Calculate
Percentage change
+25%
From 80 to 100 is an increase of 20 (25%). Going back from 100 to 80 would be -20%: the base changes, so percentages up and down do not cancel.
(B − A) ÷ |A| × 100 = (100 − 80) ÷ 80 × 100 · ratio B/A = 1.25
Calculate the percentage change from one value to another, the percentage difference between two values, what percent one number is of another, or the result of adding or subtracting a percentage.
Formula
Worked Example
The increase is 20, and 20 ÷ 80 = 0.25, or 25%. Going back down, the same 20 is divided by 100, giving −20%: changes up and down don't cancel because the base is different.
Frequently Asked Questions
What's the difference between percentage change and percentage difference?
Percentage change has a direction: it runs from an old value to a new one and divides by the old value. Percentage difference compares two values with no before and after and divides by their average, so 80 and 100 differ by 20 ÷ 90 = 22.2%.
What is a percentage point?
The arithmetic difference between two percentages. A rate that rises from 4% to 5% has gone up one percentage point, which is a 25% increase in the rate itself. Interest rates, polls and tax rates are usually compared in percentage points.
If a price falls 50% and then rises 50%, is it back where it started?
No. $100 down 50% is $50, and $50 up 50% is $75. To undo a fall of x%, you need a rise of x ÷ (100 − x) × 100%, so a 50% fall needs a 100% gain.