How to Calculate Percentage Difference In Google Sheets

When comparing two values in Google Sheets—like site visits or someone’s height—it’s not always about which one came first. That’s where percentage difference comes in. Unlike percentage change, it treats both values equally. In this post, I’ll show you how to calculate the percentage difference in Google Sheets with a simple, accurate formula. There’s no built-in function in Sheets specifically for this.

Before we go into the formula, it’s important to understand the difference between percentage difference and percentage change.

We typically use percentage change when comparing an old value (like last month’s production) with a new value (this month’s production).

But percentage difference is a bit different — it gives equal weight to both values and is best when neither value is a clear “starting” point.

Table of Contents

A Simple Example

Assume I published two Google Sheets tutorials on 01-10-2021.

Here’s the site traffic (number of visitors) to those two tutorials:

Tutorial 1: 500
Tutorial 2: 450

To manually calculate the percentage difference, use this formula:

Formula syntax:

=(absolute difference of the two values) / (average of the two values)

Since we’re interested in the absolute difference, we ignore the sign of the result.

Example calculation:

=(500 - 450) / ((500 + 450) / 2)

Result: 0.1053, which equals 10.53%

Formula to Calculate Percentage Difference in Google Sheets

Let’s put those two values in cells A1 and A2. Then, in cell B1, enter:

=TO_PERCENT(
   DIVIDE(
      ABS(MINUS(A1, A2)), AVERAGE(A1:A2)
   )
)

This formula uses:

MINUS(A1, A2) to find the difference
ABS(...) to get the absolute value
AVERAGE(...) to calculate the mean
DIVIDE(...) to divide the absolute difference by the average
TO_PERCENT(...) to format the result as a percentage

You can also simplify the formula using arithmetic operators:

=TO_PERCENT(ABS(A1 - A2) / AVERAGE(A1:A2))

Another Example: Comparing Heights

Let’s say we’re comparing the heights of two goalkeepers:

Goalkeeper 1: 6.3 ft
Goalkeeper 2: 6.5 ft

Enter 6.3 in B1 and 6.5 in B2. Then use the following formula in B3:

=TO_PERCENT(ABS(B1 - B2) / AVERAGE(B1:B2))

Percentage difference of height between two people in Google Sheets

The result will be 3.13%, which is the percentage difference in their height.

Note: Whether you input height in feet, centimeters, or inches, the result will remain the same, since we’re comparing relative difference.