About this average calculator
The word average usually means the arithmetic mean: add the numbers and divide by how many there are. Other averages suit other data. The median is the middle value and is not pulled around by a few extreme numbers, which is why it is used for incomes and house prices. The mode is the most common value. A weighted average lets some numbers count more than others, as with course credits. The geometric mean is the right average for growth rates and ratios, and the harmonic mean for rates such as speeds over equal distances. The calculator also gives the range, variance, and standard deviation, with both the population and sample formulas.
How to calculate an average
- Enter your numbers. Type or paste them separated by commas, spaces, or new lines. You can paste a column straight from a spreadsheet.
- Add weights if needed. For a weighted average, enter one weight per number in the same order. Then choose how many decimal places to show.
- Press Calculate. Read the mean, median, and mode at the top, and the full list of averages and spread measures below, each with its own Copy button.
Frequently asked questions
What is the difference between mean, median, and mode?
The mean is the sum divided by the count, the median is the middle value once the numbers are sorted, and the mode is the value that appears most often. For 2, 3, 3, 8, the mean is 4, the median is 3, and the mode is 3.
How do I calculate a weighted average?
Multiply each number by its weight, add the products, and divide by the sum of the weights. Grades 90 and 80 with weights 3 and 1 give (270 + 80) ÷ 4 = 87.5.
When should I use the geometric mean?
Use it for values that multiply together, such as yearly growth factors or investment returns. Growth of 1.10 and then 0.90 has a geometric mean of about 0.995, showing a small overall loss that the arithmetic mean of 1.00 hides.
Should I use the population or the sample standard deviation?
Use the population version when your numbers are the whole group you care about. Use the sample version, which divides by n − 1, when the numbers are a sample used to estimate a larger group.
Can a list have more than one mode?
Yes. When several values share the highest count, all of them are modes, and the calculator lists each one. When every value appears only once, there is no mode.