Use this free average calculator to find the mean of a set of numbers in seconds. Enter numbers separated by commas, and the average calculator shows the average, the sum, the count, and the lowest and highest values instantly. There is no sign-up, no account, and no personal information needed, and your numbers are calculated in your browser and are not sent to us. It works for grades, scores, prices, measurements, and any other numbers in the United States, the United Kingdom, and Canada.
Contents: Formula · How to use · Examples · Tips · FAQ · Related tools
No sign-up required. This average calculator works in your browser, so the numbers you enter are not stored or sent to us.
How to Calculate an Average: Average Calculator Formula
An average, also called the mean, is the sum of a set of numbers divided by how many numbers there are. Add all the values together, count them, and divide the total by the count. This average calculator uses exactly that method, so you can check its answer by hand.
Average = Sum of all numbers ÷ Count of numbers
For example, for 10, 20, and 30, the sum is 60 and the count is 3, so the average is 60 ÷ 3 = 20. The average calculator also shows the sum, the count, the lowest value, and the highest value, so you can see whether one very high or very low value is pulling the average away from most of the numbers. That is useful for grades and prices, where a single outlier can change the mean a lot.
How to Use the Average Calculator
Type your numbers into the box, separated by commas — for example, 10, 20, 30. Spaces after commas are fine, and decimals are fine too. Tap Calculate Average to see the average, sum, count, lowest value, and highest value. To average a new set, replace the numbers in the box and calculate again. If you enter words or blank entries, the average calculator ignores them and uses only the valid numbers.
Remember that an average is not the same as a median or a mode. The median is the middle value when the numbers are sorted, and the mode is the most common value. For a simple mean, this average calculator is the right tool. For a weighted average, where some values count more than others, use a grade calculator that lets you enter weights.
Average Calculator Examples
Example 1 — 10, 20, 30. Sum = 60. Count = 3. Average = 60 ÷ 3 = 20. Lowest = 10. Highest = 30.
Example 2 — 5, 15, 25, 35. Sum = 80. Count = 4. Average = 80 ÷ 4 = 20. Lowest = 5. Highest = 35.
Example 3 — 80, 90, 100. Sum = 270. Count = 3. Average = 270 ÷ 3 = 90. Lowest = 80. Highest = 100.
These average calculator examples show that the same average can come from very different sets: 10, 20, 30 and 5, 15, 25, 35 both average 20, but the second set is more spread out. Always look at the lowest and highest values as well as the average before drawing a conclusion.
Average Calculator Tips
Check for outliers before trusting an average, because one very large or very small value can move the mean far from the typical value. Use the same units for all numbers, and round only at the end, so rounding errors do not build up. For general background on the mean, see the Wikipedia guide to the mean. To average grades with different weights, use the semester grade calculator, and to find a final exam score, use the final grade calculator.
Average Calculator FAQ
What does an average calculator do? An average calculator adds a set of numbers together and divides the sum by the count, to give the mean, plus the sum, count, lowest value, and highest value.
How do I calculate an average by hand? Add all the numbers, count how many there are, and divide the sum by the count. For example, (10 + 20 + 30) ÷ 3 = 20.
Can I enter decimals? Yes. The average calculator accepts decimals, such as 2.5, 7.5, and 10, and gives the average to two decimal places.
What is the difference between average, median, and mode? The average is the sum divided by the count. The median is the middle value when sorted. The mode is the most common value. They can differ a lot when the data are uneven.
What if I enter a word or a blank? The average calculator ignores entries that are not numbers and averages only the valid numbers you entered.
Can I average negative numbers? Yes. Negative values are included in the sum just like positive values, so the average of −10 and 20 is 5, because (−10 + 20) ÷ 2 = 5.
Related Tools
Try the Final Grade Calculator to find a required final score, the College GPA Calculator for a GPA from course grades, the Semester Grade Calculator for a weighted semester grade, and the Percentage Increase Calculator to measure a change. Return to the PDGPT homepage to browse all free calculators by category.