Percentage Change Calculator
Find the percentage change (increase or decrease) between an old value and a new value, with the direction and amount of change shown clearly.
Percent change
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Direction
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Absolute change
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How It Works
The percentage change is the difference between the new value and the old value, divided by the absolute value of the old value, then multiplied by 100.
A positive result is a percentage increase and a negative result is a percentage decrease. The calculator reports the absolute percentage and labels the direction so it is easy to read.
The absolute change is simply the new value minus the old value. The old value cannot be zero because percentage change is undefined from a zero starting point.
Frequently Asked Questions
Why is the old value divided by its absolute value?
Using the absolute value of the old value keeps the direction of the change consistent when the old value is negative, so a positive result still means an increase.
What if my old value is zero?
Percentage change is undefined from zero, because dividing by zero is not possible. Use the absolute change instead, or pick a non-zero reference value.
Is percent change the same as percent difference?
No. Percent change compares a new value to a specific old value. Percent difference compares two values without a direction, using their average as the denominator.