# Find Missing Numbers in a Sequence in Excel

This post will guide you how to find missing numbers in a sequence with a formula in Excel. How do I identify missing numbers in a consecutive series in Excel. How to find missing serial number in Excel 2013/2016.

## Find Missing Numbers in a Sequence in Excel

Assuming that you have a serial number list in Column B, and you want to find the missing number in this sequence list. How to achieve it.

You can use an excel array formula based on the SMALL function, the IF function, the ISNA function, the MATCH function, and the ROW function. Like this:

**=SMALL(IF(ISNA(MATCH(ROW(B$1:B$20),B$1:B$20,0)),ROW(B$1:B$20)),ROW(B1))**

Type this array formula into a blank cell, and then press **Ctrl + Shift + Enter** keys in your keyboard.

The missing numbers are listed in cells.

**Note:** this formula will check the given sequence from 1 to 20 if there are missing numbers. If so, returns the missing numbers.

Or you can use another array formula based on the Small function, the IF function, the Countif function and the row function to achieve the same result. Like this:

**=SMALL(IF(COUNTIF($B$1:$B$10,ROW($1:$20))=0,ROW($1:$20),””),ROW(B1))**

### Related Functions

- Excel MATCH function

The Excel MATCH function search a value in an array and returns the position of that item.The syntax of the MATCH function is as below:= MATCH (lookup_value, lookup_array, [match_type])…. - Excel SMALL function

The Excel SMALL function returns the smallest numeric value from the numbers that you provided. Or returns the smallest value in the array.The syntax of the SMALL function is as below:=SMALL(array,nth) … - Excel ROW function

The Excel ROW function returns the row number of a cell reference.The ROW function is a build-in function in Microsoft Excel and it is categorized as a Lookup and Reference Function.The syntax of the ROW function is as below:= ROW ([reference])…. - Excel IF function

The Excel IF function perform a logical test to return one value if the condition is TRUE and return another value if the condition is FALSE. The IF function is a build-in function in Microsoft Excel and it is categorized as a Logical Function.The syntax of the IF function is as below:= IF (condition, [true_value], [false_value])…. - Excel COUNTIF function

The Excel COUNTIF function will count the number of cells in a range that meet a given criteria. This function can be used to count the different kinds of cells with number, date, text values, blank, non-blanks, or containing specific characters.etc.= COUNTIF (range, criteria)…