Percentage Change Calculator
Compare an original value with a new value to find the percentage increase or decrease. Enter the earlier amount first; the result also shows the numerical difference.
How it works
Subtract the original value from the new value. Divide that difference by the original value and multiply by 100. A positive result is an increase; a negative result is a decrease.
Worked example
An increase from 80 to 100 is (100 − 80) ÷ 80 × 100 = 25%. A decrease from 100 to 80 is (80 − 100) ÷ 100 × 100 = −20%.
Keep in mind
The original value must be greater than zero. Reversing the values changes the reference amount, so a 25% increase is not undone by a 25% decrease.
Percentage increase versus percentage decrease
Enter the earlier amount as Original value and the later amount as New value. The result names the direction of change and shows the absolute difference. For example, a price rising from 80 to 100 is a 25% increase; falling from 100 to 80 is a 20% decrease.
Percent change versus percentage points
When comparing two rates, percentage points are the simple subtraction. A rate rising from 4% to 5% rises by 1 percentage point, but the relative increase is (5 − 4) ÷ 4 × 100 = 25%. Enter 4 and 5 here to calculate the relative change.
Which calculator should I use?
Use this tool when you know an original and a new value. To ask what percent one amount is of another without comparing before and after, use the Percentage Calculator instead.