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- The average (mean) is the sum of your numbers divided by how many numbers there are.
- You also get the median, mode, range, sum, smallest and largest values, and the standard deviation.
- Open the weighted option when some numbers count more than others, for example grades with different credit hours.
- Paste your numbers separated by commas, spaces or new lines. Up to 5,000 numbers work.
How to use the average calculator
Enter your numbers
Type or paste your numbers into the box. Commas, spaces and new lines all work. Use a period for decimals and a minus sign for negatives.
Add weights if you need them
Open the weighted average option and enter one weight for each number, in the same order. Leave it empty for a simple average.
Read the mean
The average appears at the top as soon as you type, with the sum and the count behind it.
Check the spread
Compare the median, mode, range and standard deviation to see whether the mean tells the whole story.
How to calculate an average
The main measures
Mean = sum of the numbers ÷ how many numbers
Median = the middle number once they are sorted (the mean of the two middle numbers if the count is even)
Mode = the number that appears most often
Range = largest number − smallest number
Weighted average = sum of (number × weight) ÷ sum of the weights
The sample standard deviation divides by n − 1, the population version divides by n. Use the sample version when your numbers are a sample of a bigger group.
Worked examples
Five test scores
Scores of 85, 90, 78, 92 and 88.
The sample standard deviation is about 5.46, so most scores sit within a few points of the mean.
A weighted course grade
Homework is worth 20% of the grade, the midterm 30% and the final exam 50%.
The simple mean of the three scores is 84.3, but the final exam counts for half the grade, so the weighted result is lower.
Mean, median or mode?
Mean
Best when the numbers are fairly evenly spread, such as test scores or daily temperatures.
Median
Best when a few extreme values would distort the mean, such as house prices or incomes.
Mode
Best for the most common choice, such as a popular shoe size or a favorite product.
Weighted average
Use it when items do not count equally, such as grades, investment returns or survey groups of different sizes.
The prices 30, 32, 35, 36 and 400 have a mean of 106.6 but a median of 35. The single 400 drags the mean far above what is typical. When you spot outliers, compare the median as well.
Average calculator FAQ
How do you calculate the average of a set of numbers?
Add all the numbers together and divide by how many there are. For 4, 8 and 15 the sum is 27 and the average is 27 ÷ 3 = 9.
Is the average the same as the mean?
In everyday use, yes. The average usually means the arithmetic mean. The median and the mode are other ways to describe the center of a set of numbers.
Can a data set have no mode, or more than one?
Yes. If every value appears once there is no mode. If two or more values tie for most frequent, the data has several modes, and the calculator lists up to five.
How do I calculate a weighted average?
Multiply each number by its weight, add the results, then divide by the sum of the weights. In the calculator, open the weighted average option and enter one weight per number in the same order.
What is the difference between sample and population standard deviation?
Population standard deviation is for when you have every value in the group. Sample standard deviation is for when your numbers are only a sample, and it divides by n − 1 to correct for that.
Can I average percentages, negatives or decimals?
Yes for negatives and decimals. For percentages, a simple average is only right when every percentage is out of the same total. Otherwise use a weighted average with the group sizes as weights.
Related calculators
Need the smallest number that several numbers all divide into? Try the LCM calculator, which shows the least common multiple with steps.