Average four scores
The mean of 78, 84, 91, and 87 is (78 + 84 + 91 + 87) / 4 = 340 / 4 = 85.
Find the arithmetic mean
Average calculator
Paste or type a list of values to find its average, total, and count without building a spreadsheet formula.
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Formula
The arithmetic mean formula
Arithmetic mean = (x₁ + x₂ + ... + xₙ) / n
The arithmetic mean, usually called the average, gives every entered value equal weight. Add the values and divide by how many values were included.
An average describes the center of a list but does not show its spread. A very high or low outlier can pull the mean away from where most values sit.
How to use the formula
List the values
Include each observation once for every time it should count in the average.
Add the values
Find the sum, keeping negative signs and decimal places with their numbers.
Count the values
Count observations rather than separators or blank entries.
Divide the sum by the count
The quotient is the arithmetic mean. Round only when the needed precision is known.
Worked examples
Average calculator examples
Average monthly costs
The mean of 42.50, 38.00, and 45.50 is 126 / 3 = 42.
Common questions
Average calculator FAQ
Is the average the same as the median?
Not always. The mean adds every value and divides by the count, while the median is the middle value after sorting. Outliers usually affect the mean more.
Do repeated numbers count more than once?
Yes. Each entered value is one observation, so a repeated number counts each time it appears.
Can an average include negative numbers and decimals?
Yes. Add negative numbers and decimals normally, then divide the total by the number of observations.
Is my list saved or uploaded?
Your list is not saved by default or uploaded. You can opt into Remember on this device or download a local JSON backup.