You can use the following basic formula to average every nth row in Excel:
=AVERAGE(IF(MOD(ROW(A2:A21)-MIN(ROW(A2:A21)),n)=0,A2:A21))
This formula calculates the average of every nth value in the range A2:A21.
Simply change the value for n in the formula to average specific rows.
For example, you can use the following formula to average every 4th row:
=AVERAGE(IF(MOD(ROW(A2:A21)-MIN(ROW(A2:A21)),4)=0,A2:A21))
The following examples show how to use this formula in practice.
Example: Average Every Nth Row in Excel
Suppose we have the following column of values in Excel:
We can use the following formula to calculate the average of every 4th row from column A:
=AVERAGE(IF(MOD(ROW(A2:A21)-MIN(ROW(A2:A21)),4)=0,A2:A21))
The following screenshot shows how to use this formula in practice:
The formula shows that the average of every 4th row in the range A2:A21 is 18.
We can verify this is correct by manually identifying each 4th value in the range:
The average of these values can be calculated as:
Average = (4 + 10 + 17 + 29 + 30) / 5 = 18
If we change the value of n in the formula, we can select a different nth value.
For example, we can use the following formula to calculate the average of every 6th row in the range:
=AVERAGE(IF(MOD(ROW(A2:A21)-MIN(ROW(A2:A21)),6)=0,A2:A21))
The following screenshot shows how to use this formula in practice:
The formula shows that the average of every 6th row in the range A2:A21 is 18.25.
We can verify this is correct by manually identifying each 6th value in the range:
The average of these values can be calculated as:
Average = (4 + 15 + 29 + 25) / 4 = 18.25
This matches the value calculated by our formula.
Additional Resources
The following tutorials explain how to perform other common operations in Excel:
How to Select Every Nth Row in Excel
How to Sum Every Nth Row in Excel
How to Select Every Other Column in Excel