Using the SUM formula this way will allow your data tables to grow and include any new items by running totals.

Syntax

=SUM(Absolute reference, Relative reference)

Steps

  1. Type SUM function with a range that contains only single cell =SUM(C3:C3)
  2. Make range’s first cell absolute by clicking on it and pressing F4 key =SUM($C$3:C3)
  3. Copy down the formula all the way down =SUM($C$3:C8)

How

The trick is using a mixed reference to expand formula range cell by cell. Formula range expands by relative reference while absolute reference is locked at cell. As a result; SUM function calculates one cell more with every new cell.

See also SUMIF and SUMIFS formulas.