Average Calculator

Average calculator at a glance#

An average calculator finds the average of a set of numbers. The average is the sum of all the values divided by how many values there are. Add the numbers together, count them, then divide the sum by the count. The average is the same as the arithmetic mean.

Worked example: for 10, 20, 30 and 40, add them to get a sum of 100. There are 4 values, so divide 100 by 4 to get an average of 25. Written as a formula, average = sum / count, which here is 100 / 4 = 25.

Enter your numbers in the calculator above for the exact average, with the running sum, the count and the steps shown. The result can carry decimals when the sum does not divide evenly by the count, so it may be rounded for display.

How the average works#

The average, also called the arithmetic mean, is the sum of your numbers divided by how many numbers there are. Add every value, count the values, then divide the total by the count. The result sits in the middle of the data in the sense that it balances the values above and below it.

The average can land on a number that is not in your list, and it can carry decimals. For 4, 5 and 9 the sum is 18 and the count is 3, so the average is 18 divided by 3, which is 6. For 3 and 4 the average is 3.5, a value that appears in neither input.

How to enter your numbers#

Type your values into the calculator separated by commas or on separate lines. It returns the average along with the running sum and the count, so you can check each step. Negative numbers and decimals work the same way and are included in both the sum and the count.

Where the average is used#

• School and test scores: averaging marks to a single grade.
• Money: average monthly spend, average order value, average price.
• Sport and fitness: average pace, average reps, average score per game.
• Measurements: averaging repeated readings to smooth out noise.

Average vs median#

The average uses every value, so a single very large or very small number pulls it up or down. The median is the middle value once the numbers are sorted, and it ignores how extreme the outliers are. For 2, 3, 4, 5 and 100 the average is 22.8 but the median is 4. When a few outliers skew the data, the median often describes the typical value better; when the data is even, the average is the simpler summary. Use the median calculator if you need the middle value instead.

Frequently asked questions#

How do I find the average of a set of numbers?#

Add all the numbers, then divide the total by how many numbers you added. For 10, 15, 20, 25 and 30 the sum is 100 and the count is 5, so the average is 100 divided by 5, which is 20.

Can you give a worked example?#

Take 4, 8 and 12. The sum is 24 and there are 3 values, so the average is 24 divided by 3, which is 8. The calculator shows the same sum, count and division steps.

Does it handle decimals?#

Yes. Decimal inputs go into the sum and count unchanged. For 2.5, 3.75 and 4.1 the sum is 10.35 and the count is 3, so the average is about 3.45.

Is the average the same as the mean?#

Yes. The plain average is the arithmetic mean: sum divided by count. Other means exist, such as the geometric mean, but this tool computes the everyday arithmetic average.