Excel SUM and AVERAGE Functions

SUM and AVERAGE are the two most-used Excel functions for totaling a range of numbers and finding their typical value.

Adding Up Numbers with SUM

SUM adds together every number in the range or list you give it. Its syntax is SUM(number1, [number2], ...), where each argument can be a single cell, a range like B2:B10, or a typed-in number, and you can mix several of them separated by commas.

Example

=SUM(B2:B10)

SUM automatically skips over empty cells and text, so a stray label mixed into a numeric range will not break the total, it simply gets ignored.

Finding the Typical Value with AVERAGE

AVERAGE computes the arithmetic mean of a range: it adds up every number and divides by how many numbers it found. Its syntax mirrors SUM: AVERAGE(number1, [number2], ...).

Example

=AVERAGE(B2:B10)
Note: AVERAGE ignores blank cells when counting how many values to divide by, but a cell containing 0 is counted as a real value. Mixing up "blank" and "zero" is a common cause of an average looking lower than expected.

Related Aggregate Functions

FunctionPurpose
SUMAdds every number in a range.
AVERAGECalculates the arithmetic mean of a range.
COUNTCounts how many cells in a range contain numbers.
MAXReturns the largest number in a range.
MINReturns the smallest number in a range.

Both SUM and AVERAGE accept multiple ranges at once, which is handy when the numbers you need are not next to each other, for example =SUM(B2:B10, D2:D10) adds two separate columns in a single formula.

Note: Select a range of numbers and look at the status bar along the bottom of the Excel window: it automatically shows the Sum, Average, and Count of the selection without writing any formula at all.