Often you may want to convert monthly data into quarterly data.

For example, you might have a dataset that contains information about total sales each month during a particular year and you want to convert this monthly data into quarterly data:

Fortunately this is easy to do in Excel and the following step-by-step example shows how to do so.

**Step 1: Enter Original Data**

First, we will enter the following dataset into Excel that shows the total sales each month at some retail store:

**Step 2: Create List of Quarters**

Next, we can type out a list of quarters into column D:

**Step 3: Calculate Sum of Each Quarter**

Lastly, we can type the following formula into cell **E2** to calculate the sum of sales for the first quarter:

=SUM(OFFSET(B$2,3*ROWS(B$2:B2)-3,,3))

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

From the output we can see:

- The total sales for the first quarter (Jan, Feb, Mar) was
**502**. - The total sales for the second quarter (Apr, May, Jun) was
**622**. - The total sales for the third quarter (Jul, Aug, Sept) was
**619**. - The total sales for the fourth quarter (Oct, Nov, Dec) was
**738**.

We have now successfully converted the monthly data to quarterly data.

**Note**: In this example we used the **SUM** function to calculate the sum of sales for each quarter, but you could instead use a different function such as the **AVERAGE** if you’d like to calculate the average sales each quarter.

**Additional Resources**

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

How to Group Data by Quarter in Excel

How to Sum by Quarter in Excel

How to Convert Date to Quarter and Year in Excel