Average Calculator

Enter any list of numbers to get the average — the arithmetic mean — instantly, with every step shown: add the values, then divide by how many there are.

Average (mean) —
Sum —
Count (n) —

How to Find the Average of a List of Numbers

The average (mean) is the sum of the numbers divided by how many numbers there are.

1

Add the numbers together

Add every value in your list to get the sum. For 80, 90, 100 the sum is 80 + 90 + 100 = 270. Decimals and negative numbers are added the same way.

2

Count how many numbers there are

Count the values in the list — this is n. In the example there are 3 numbers, so n = 3.

3

Divide the sum by the count

Divide the sum by n to get the average: 270 ÷ 3 = 90. That is the arithmetic mean. Need the median and mode as well? Use the Mean, Median, Mode Calculator.

Frequently Asked Questions

How do you calculate the average?
Add all the numbers together to get the sum, then divide by how many numbers there are (the count). For example, the average of 4, 8 and 15 is (4 + 8 + 15) ÷ 3 = 27 ÷ 3 = 9. The calculator shows this working for any list of numbers.
Is the average the same as the mean?
The average and the arithmetic mean are the same thing in everyday use: the sum of the values divided by how many there are. The average of 4, 8 and 15 is 27 ÷ 3 = 9. There are other kinds of average — the median, which is the middle value, and the mode, which is the most frequent value — and they describe the centre of a data set differently. To see all three at once, use the Mean, Median, Mode Calculator.
How do you find the average of 3 numbers?
Add the three numbers together and divide by 3. For example, (10 + 20 + 30) ÷ 3 = 60 ÷ 3 = 20. For 2 numbers you divide by 2, for 4 numbers you divide by 4, and so on — always divide the sum by the count.
Does it work with decimals and negative numbers?
Decimals and negative numbers are both supported. The average is found the same way: add the values, respecting any negative signs, and divide by the count — the average of −4, 2 and 8 is 6 ÷ 3 = 2. The calculator accepts values separated by commas, spaces or new lines. Mixing decimals and negatives in one list is fine.

Related Calculators

The mean is only one summary of a data set. The Mean, Median, Mode Calculator gives all three centre measures at once, the Standard Deviation Calculator and the Variance Calculator describe the spread around the mean, and the Percentile Calculator shows where a single value sits in the distribution.