Free calculator
Percentage Increase Calculator
Enter a starting and ending value. The result shows the percentage change, the absolute difference and the multiplier.
Percentage change formula
The change is (new − old) ÷ old × 100. A move from 80 to 100 is 20 ÷ 80 × 100 = 25%. A move from 100 to 80 is −20 ÷ 100 × 100 = −20%: the same absolute difference, a different percentage, because the base changed.
Percentage points vs percent
If an interest rate rises from 2% to 3%, that is one percentage point but a 50% relative increase. Mixing the two is one of the most common errors in finance and statistics.
Reverse the calculation
To find the original value after a known change, divide by the multiplier. A price of $125 after a 25% increase came from 125 ÷ 1.25 = 100. To reverse a 20% decrease, divide by 0.8, not multiply by 1.2.
Frequently asked questions
How do I calculate a percentage increase?
Subtract the old value from the new one, divide by the old value and multiply by 100.
What is the difference between percent and percentage points?
A change from 2% to 3% is one percentage point but a 50% relative increase.
How do I reverse a percentage increase?
Divide the final value by 1 plus the rate. After a 25% increase, divide by 1.25.
Can the result be negative?
Yes. A decrease produces a negative percentage; the page labels it as a decrease.