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Percentage Change Calculator
Percentage change tells you how much a value grew or shrank relative to its starting point. Enter the original and new values, and this calculator gives the percentage increase or decrease, the raw difference, and a plain-English summary of the move.
Results
Difference (new - original)
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Percentage change
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Summary
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How it works
Percentage change measures movement relative to where you started. The formula is (new value - old value) / old value x 100. A rise from 50 to 75 is (75 - 50) / 50 = 50 percent. A fall from 75 back to 50 is (50 - 75) / 75 = -33.3 percent, not -50 percent, because the base changes: losses and gains are measured against the value you started that leg with. This asymmetry explains why a 50 percent loss needs a 100 percent gain to recover. The other classic confusion is percentage points: when an interest rate rises from 4 percent to 6 percent, that is an increase of 2 percentage points, but a 50 percent relative increase. News reports that mix the two can mislead by an order of magnitude. Percentage change also breaks down at zero: if the original value is 0, the change is undefined rather than infinite, and if the new value is 0, the result is a clean -100 percent. This calculator reports the change, the new-minus-old difference and the direction, so increases and decreases read unambiguously.
Frequently asked questions
How do you calculate percentage change?
Divide the change by the original value and multiply by 100. A move from 50 to 75 is an increase of 25, which is 50 percent of the original 50.
Is a percent the same as a percentage point?
A percent is a share of a fixed whole (say 50 percent of 200). A percentage point is the direct difference between two percentages: rising from 4 percent to 6 percent is a 2 percentage point move but a 50 percent increase.
Why is going up 50 percent and back down not 50 percent?
Start from the new value: (old - new) / old is negative in reverse, so 75 back to 50 is a decrease of 33.3 percent, because the base (75) is bigger.
Can percentage change be more than 100 percent?
No. If the new value is 0, the decrease is exactly 100 percent. If the original value is 0, percentage change is undefined, since you cannot divide by zero.