# Excel: How to Convert Monthly Data to Quarterly Data

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.