Do you need to calculate the average age? It is very simple. All you need to do is use a simple three-step process and you can calculate the average yourself.

## Steps

### Part 1 of 3: Calculate Average Age

#### Step 1. Organize all the ages on the list

Calculating the average of a data set is very simple. It means that you have to take all the numbers from a list and then write them down on a sheet of paper or a spreadsheet.

#### Step 2. Find the sum of all the ages on the list

That means you have to add them all together to get the total. Let's say you are 5 ages: 31, 30, 26, 21, 10. The total or sum of those numbers is 118.

#### Step 3. Now, divide the sum you got by the number of ages on the list

That is the average. Using the example above, you need to divide 118 (the sum of all ages) by 5 (the number of ages in the list). The average age is 23, 6.

### This works with longer lists of numbers. For example, let's say you want to find the average age of a group of people in a club and there are 100 members in that group. You need to know the exact age of each of them. Then you need to add all those ages to get the total. Then divide the sum by the number 100. That is the average age of the club members

#### Step 4. Find the average of another set of numbers

There is no difference when calculating the average for other types of numbers that are not ages. The average works the same way.

- For example, let's say you want to know the average population of the 10 largest cities in America. You have to write down the number of the population of each country. Next, you need to add all those numbers. Now divide that sum by 10 and that's the average.
- There are times when you need to use the weighted average. For example, when averaging a student's grade, you can weight some assignments so that they are worth more than others. To do this, multiply each grade by the weighted grade. Then add up those numbers and divide by the total number of grades.

### Part 2 of 3: Determine When to Use Average

#### Step 1. Understand the difference between average and median

Sometimes people confuse the difference between the mean and the median of a set of numbers. In fact, there are times when the median is better than the average.

- The median is the middle number in a set of information. The median is the number (in this case the age) that appears exactly in the middle.
- Obtaining the median may be a better assessment of age if there is an isolated case in the group. Let's say all the college students in a class of 20 are between the ages of 18-25, but there is only one student older than 80. If you take the average, that 80-year-old student will cause the average to skyrocket upward, making it appear that the students in the class are older than they actually are. If you select a number in the middle of all the ages in the list, this will be a more accurate representation of the class. For this reason, it is best to use a median if there is an isolated case on your list.

#### Step 2. Find out how the mode differs from the median or the average

Fashion is different; the mode is the number that appears the most times in the information set.

- The mean is the same as the average. The mean is just another word used to describe the mean. Sometimes the best way to work with numbers is to present more than a single number, in this case it would be the median and the average.
- If you are asked to find the average age but you only have one age range (such as a certain number of people between 2 and 4 years old and another number of people between 4 and 6 years old, you can calculate the midpoint of each age range, add those two and then divide them by the total of numbers in each age range).

### Part 3 of 3: Finding Average Age with Many Numbers

#### Step 1. Try using an Excel spreadsheet

If you need to average a very long list of ages, try putting them in an Excel list. Otherwise, if you write it down on paper and use a calculator, it will take you a long time.

- Let's say you need to calculate the average age of all the students in a school or of all the people on the payroll of a large company. These are examples where the list will be many different ages so it is best to use a spreadsheet program like Excel.
- The first thing you need to do is put all the ages in the Excel spreadsheet. Excel is a well-known program that you can get through the Microsoft Office package. You can write all the ages yourself in Excel or, better yet, import another document that already has the ages directly into Excel. Maybe you already have the ages organized in Excel.
- To import a file into Excel, click on the option "Get external information" and on the text. Excel will open a wizard that will tell you how to import the information into the spreadsheet.

#### Step 2. Use the Excel formula to get the average

Assuming the ages are in column A in Excel. Let's say they start at row 1 and end at row 200 (columns are vertical in Excel and rows are horizontal). To get the average, you need to enter the Excel formula to get the average. You can write at the end of column A.

- The formula to get the average in Excel is "= (AVERAGE) A1: A200". You need to substitute the coordinates of the column and the row containing the first age in the column by A1. In this example, since the first age is in column A1, it stays the same in the formula. You also need to substitute A200 for the column and row coordinates that contain the last age in your list.
- In this example, A200 is left because the last age in the list is in column A, row 200. The colon (:) between the values tells the computer to add up all the ages in the cell. A1 to cell A200 and then take the average. Press "Enter" and the average will appear.

#### Step 3. Try using an average calculator

These are websites that make it much easier to calculate the average. These sites provide online calculators into which you can enter a large number of numbers.