Percentage change calculator.
Find the percent increase or decrease between two numbers. Enter the old value and the new value and the calculator gives the percentage change and the absolute difference.
Old and new value
LivePercentage change is the new value minus the old value, divided by the old value, times 100. A negative result is a decrease.
Percentage change
+25%
from old to new
Uses the absolute value of the old value as the base, so the old value cannot be zero. Calculations run in your browser; nothing you enter is stored.
How it works
From old to new
Percentage change measures how much a number has grown or shrunk relative to where it started. You take the difference between the new and old values, divide by the old value, and multiply by 100.
Going from 120 to 150 is a rise of 30 on a base of 120, which is a 25% increase. A drop from 120 to 90 is a 25% decrease. The sign tells you the direction.
Reference
Percentage change examples.
How everyday old-to-new pairs translate into a percentage change.
| Old to new | Change |
|---|---|
| 50 to 75 | +50% |
| 200 to 150 | -25% |
| 80 to 100 | +25% |
| 120 to 90 | -25% |
| 40 to 60 | +50% |
The full guide
The complete guide to percentage change.
How to calculate it, why the base matters, and where increase and decrease differ.
How to calculate percentage change
Subtract the old value from the new value to get the difference, divide by the old value, and multiply by 100. A positive answer is an increase and a negative answer is a decrease.
From 120 to 150 the difference is 30, and 30 divided by 120 is 0.25, so a 25% increase. The same method works for any pair of numbers.
Why the starting value matters
Percentage change is always relative to the old value, the base. The same absolute change is a bigger percentage when the base is small and a smaller percentage when the base is large, which is why context matters.
A 10 unit rise from 20 is 50%, but a 10 unit rise from 200 is only 5%.
Increase, decrease and reversibility
A percentage increase and the percentage decrease that undoes it are not the same size, because the base changes. Going up 25% from 120 reaches 150, but getting back from 150 to 120 is a 20% decrease, not 25%.
This asymmetry trips people up with prices, weights and investment returns.
Percentage change versus percentage point
Percentage change is a relative measure. A percentage point is an absolute gap between two percentages. Moving from 10% to 15% is a 5 percentage point rise but a 50% increase. Keeping the two ideas separate avoids confusion in reports.
This calculator gives the relative percentage change between your two values.
The formula
Old to
new.
Percentage change is the difference between the new and old values, divided by the old value, times 100. A negative result is a decrease.
Percentage calculator ›# Percentage change
change = (new - old) / |old| × 100
# example
(150 - 120) / 120 × 100 = +25%Questions
Percentage change questions.
How do I calculate percentage change?
+
Subtract the old value from the new value, divide by the old value, and multiply by 100. From 120 to 150 that is 30 / 120 times 100, a 25% increase.
Is percentage change the same as percentage difference?
+
No. Percentage change compares a new value to an old one with a clear direction. Percentage difference compares two values symmetrically, dividing by their average, with no before or after.
Why is a 25% rise not undone by a 25% fall?
+
Because the base changes. A 25% rise from 120 gives 150, but returning from 150 to 120 is a 20% fall, since the base is now larger.
Can the old value be zero?
+
No. Percentage change divides by the old value, so a starting value of zero leaves the percentage undefined. Enter a non-zero old value.
Is this percentage change calculator free?
+
Yes. It is completely free with no sign-up, and every calculation runs locally in your browser, so nothing you enter is stored or sent anywhere.
About the developer
Jean Borg
Jean builds and maintains every calculator on freecalculators.pro from Malta, with a focus on tools that are fast, free and show their working. The percentage change calculator uses the standard relative-change formula and shows the difference too.