The SUM function adds numbers in Excel from cells, ranges, or individual values. This guide explains how SUM works and includes practical examples you can use immediately.

WHAT THE SUM FUNCTION DOES

The SUM function totals numeric values across one or more cells. It's commonly used for adding expenses, summing sales or quantities, and combining values across different ranges in spreadsheets.

WHEN TO USE SUM

Use SUM when you want to:

  • Add numbers in a column or row
  • Total expenses, sales, or quantities
  • Combine multiple ranges into one total
  • Build budgets, models, or reports that need totals
FORMULA SYNTAX
SUM(number1, [number2], ...)
ArgumentDescription
number1The first number, cell reference, or range
number2Additional numbers, cell references, or ranges (optional)
EXAMPLE 1: SUM A COLUMN OF EXPENSES

We want to calculate the total monthly expenses.

AB
1ExpenseAmount
2Rent1200
3Utilities150
4Groceries300
5Gas80
6Total=SUM(B2:B5)
=SUM(B2:B5)

Result: 1730 (1200 + 150 + 300 + 80)

Need help applying this? Try this in Numstro Builder

EXAMPLE 2: SUM MULTIPLE RANGES AND INDIVIDUAL CELLS

We want to total quarterly sales across several columns plus a bonus.

ABCD
1Q1Q2Q3Q4
25000600055007000
3Bonus: 1000
=SUM(A2:D2, A3)

Result: 24500 (5000 + 6000 + 5500 + 7000 + 1000)

Need help applying this? Try this in Numstro Builder

COMMON MISTAKES & EDGE CASES
  • Text values are ignored (treated as 0)
  • Empty cells are ignored
  • Error values (#DIV/0!, #VALUE!) break the result
  • SUM can handle up to 255 separate inputs
  • Use SUMIF or SUMIFS when you need conditional totals
RELATED FUNCTIONS
  • SUMIF — sum with one condition
  • SUMIFS — sum with multiple conditions
  • COUNT — count numbers
  • AVERAGE — calculate the mean
FURTHER READING

Official Microsoft documentation:
SUM — Microsoft Support