You can use the following formula to calculate a cumulative sum by group in Excel:

=SUMIF(A$2:A2,A2,B$2:B2)

This particular example assumes that the group values are in column A and the values to sum are in column B.

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

**Example: Calculate Cumulative Sum by Group in Excel**

Suppose we have the following dataset that shows the points scored by basketball players on various teams:

Suppose we would like to calculate the cumulative points for each team.

We can type the following formula into cell **C2** to do so:

=SUMIF(A$2:A2,A2,B$2:B2)

We can then click and drag this formula down to each remaining cell in column C:

Column C displays the cumulative points values for each team.

For example:

- The cumulative points for
**Mavs**is: 22, 36, 56 - The cumulative points for
**Warriors**is: 17 - The cumulative points for
**Hawks**is: 33, 53, 77 - The cumulative points for
**Kings**is: 28, 53 - The cumulative points for
**Blazers**is: 18, 31, 41

Notice that the values in the cumulative sum column restart for each new team name.

**Note**: This formula works even if each of the team names are not grouped together.

**Additional Resources**

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

How to Calculate the Sum by Group in Excel

How to Calculate Relative Frequency in Excel

How to Calculate Cumulative Frequency in Excel