To count unique values in a range with a criteria, you can use an array formula based on the FREQUENCY function.
Assume you have a list of employee names together with hours worked on "Project X", and you want know how...

To sum the last n columns in a table of data (i.e. last 3 columns, last 4 columns, etc.) you can use a formula based on the INDEX function. In the example shown, the formula in K5:
=SUM(INDEX(data,0,COLUMNS(data)-(K4-...

One way to extract data in Excel is to use INDEX and MATCH with a helper column that marks matching data. This avoids the complexity of a more advanced array formula.
In the example shown, the formula in H6 is:
=IF($...

To count unique numeric values in a range with criteria you can use a formula based on the SUM and FREQUENCY functions, together with the IF function to apply criteria.
For example, assume you have a list of employee...

To calculated a weighted average, you can use the SUMPRODUCT function together with the SUM function. In the example shown, the formula in G7 is:
=SUMPRODUCT(C5:C11,D5:D11)/SUM(D5:D11)
How this formula works
The...

To allow only values that don't exceed a set sum, you can use data validation with a custom formula based on the SUM function. In the example shown, the data validation applied to B5:B9 is:
=SUM($C$6:$C$9)<=1000...

To sum a total in multiple tables, you can use the SUM function and structured references to refer to the columns to sum. In the example shown, the formula in I6 is:
=SUM(Table1[Amount],Table2[Amount])
How this...

To create a running total in an Excel Table, you can use the INDEX function set up with a structured reference. In the example shown, the formula in F5 is:
=SUM(INDEX([Total],1):[@Total])
When copied down the column...

To sum all values in a column or row, you can use the INDEX function to retrieve the values, and the SUM function to return the sum. This technique is useful in situations where the row or column being summed is...

If you want to sum an entire column without supplying an upper or lower bound, you can use the SUM function with and the specific range syntax for entire column.
In the example shown, the formula in G6 is:
=SUM(D:D...

To sum a set of monthly data through n number of months, you can use a formula based on the SUM and OFFSET functions. In the example shown, the formula in G6 is:
=SUM(OFFSET(C5,0,0,G5,1))
How this formula works
In...

To sum based on multiple criteria using OR logic, you can use the SUMIFS function with an array constant. In the example shown, the formula in H6 is:
=SUM(SUMIFS(E4:E11,D4:D11,{"complete","pending...

To lookup and return the sum of a column, you can use the a formula based on the INDEX, MATCH and SUM functions. In the example shown, the formula in I7 is:
=SUM(INDEX(C5:F11,0,MATCH(I6,C4:F4,0)))
How this formula...

To calculate a running total, you can use the SUM formula with a mixed reference that creates an expanding range. In the example shown, the formula in cell D6 is:
=SUM($C$6:C6)
When this formula is copied down the...

To sum the top values in a range, you can use a formula based on the LARGE function, wrapped inside the SUMPRODUCT function. In the generic form of the formula (above), rng represents a range of cells that contain...