PERCENTAGE DIFFERENCE CALCULATOR

Compare two numbers of equal standing






Percentage difference is not the same as percentage change. It compares two values with no "before" and "after" — neither number is treated as the starting point. Instead, both values share the denominator equally, using their average. This makes the result the same no matter which value you enter first.

Percentage difference formula: absolute value of A minus B, divided by the average of A and B, times 100

Example
Two stores sell the same blender: Store A for $80, Store B for $100. What is the percentage difference?
|80 - 100| / ((80 + 100)/2) × 100 = 20 / 90 × 100 = 22.22
The percentage difference is 22.22%.



Example
Two students measure their plant's height: 150 cm and 165 cm. What is the percentage difference?
|150 - 165| / ((150 + 165)/2) × 100 = 15 / 157.5 × 100 = 9.52
The percentage difference is 9.52%.

Example
Two surveys report approval ratings of 45% and 52%. What is the percentage difference between the two results?
|45 - 52| / ((45 + 52)/2) × 100 = 7 / 48.5 × 100 = 14.43
The percentage difference between the two survey results is 14.43%. (Note: since these inputs are already percentages, the 7-point gap is also expressed in percentage points.)

When to use this calculator

Use percentage difference when neither number is the "before" and neither is the "after" — two prices from two stores, two measurements, two survey results. If one value is clearly the starting point and the other the result over time, use the percentage change calculator instead; it will give a different (and directional) answer.

Frequently asked questions

Does the order of the two values matter?
No. Percentage difference is symmetric — entering A and B gives the same result as entering B and A.

Can I use negative numbers?
The formula is best suited to positive values. With mixed signs or values that sum to zero, the result becomes undefined or misleading.

Is this the same as percentage change?
No. Percentage change treats one value as the starting point; percentage difference treats both values equally. Related: percentage change calculator and percentage points vs percentage change.