You can use the following basic formula to sum every nth row in Excel:

=SUM(A1:A20*(MOD(ROW(A1:A20),4)=0))

This particular formula calculates the sum of every **4th** row in the range **A1:A20**.

Simply change the value in the **ROW()** function to sum a different interval of rows.

For example, you can use the following formula to sum every **3rd** row:

=SUM(A1:A20*(MOD(ROW(A1:A20),3)=0))

The following example shows how to use this formula in practice.

**Example: Sum Every Nth Row in Excel**

Suppose we have the following list of values in Excel:

We can use the following formula to sum every **fourth** row in the range:

=SUM(A1:A20*(MOD(ROW(A1:A20),4)=0))

The following screenshot shows how to use this formula in practice:

We can see that the sum of the values in every 4th row is **66**.

We can verify this is correct by manually calculating the sum of every 4th row:

Sum of Every 4th Row: 10 + 19 + 8 + 24 + 5 = **66**.

If you’d like to sum the value of every nth row starting with the *first* row, you can subtract 1 within the **ROW()** function of the formula:

=SUM(A1:A20*(MOD(ROW(A1:A20)-1,4)=0))

The following screenshot shows how to use this formula in practice:

We can verify that this formula calculates the sum of every 4th row starting with the first row:

Sum of Every 4th Row: 8 + 5 + 14 + 12 + 29 = **68**.

This matches the value calculated by the formula.

**Additional Resources**

The following tutorials explain how to perform other common operations in Excel:

How to Sum Filtered Rows in Excel

How to Select Every Nth Row in Excel

How to Count Rows with Value in Excel