Percent change calculator
Enter the old value and the new one. The answer is signed: + for a rise, − for a fall.
Percent change
How much a value went up or down, as a percentage of where it started. A rise shows as +, a fall as −.
From to
Working: (65 − 50) ÷ 50 × 100 = +30%
- Difference
- +15
Percent difference
For two values where neither is the “before”, like two quotes for the same job. It divides the gap by their average, so swapping them gives the same answer. Percent change is different: it depends on which value came first.
Between and
Working: |50 − 65| ÷ ((50 + 65) ÷ 2) × 100 = 26.087%
- Average
- 57.5
Percentage points vs percent
When the numbers are themselves percentages, the plain gap between them is in percentage points. An interest rate going from 4% to 5% is up 1 percentage point, but up 25% compared with what it was. Both are right; they answer different questions.
A rate goes from to
Working: 5 − 4 = 1 point
- Relative change
- (5 − 4) ÷ 4 × 100 = +25%
The formula
Subtract the old value from the new one, divide by the old value, and multiply by 100. From 50 to 65 is (65 − 50) ÷ 50 × 100 = +30%.
Going back down is a different percentage
From 65 back to 50 is (50 − 65) ÷ 65 × 100 = −23.08%. The starting point changed, so the percentage did too. It's why a 50% fall needs a 100% rise to get back.
Zero and negative starting values
A change from zero can't be expressed as a percentage, since any rise is infinitely large compared with nothing. With a negative start, this page divides by its size, so −50 to −25 counts as a 50% increase. Not every textbook does that, so check what your course expects.
Which one do I want?
Percent change when there's a before and an after. Percent difference when there isn't, like the prices at two shops. Percentage points when both numbers are already percentages, like interest rates or poll results.