Performing a Lookup with Unsorted Data in Excel

The information in this article applies to:

• Microsoft Excel for Windows, versions 2.x, 3.x, 4.x
• Microsoft Excel for OS/2, versions 2.2, 2.21, 3.0
• Microsoft Excel for the Macintosh, versions 2.x, 3.x, 4.0

SUMMARY

In Microsoft Excel, the VLOOKUP function searches the leftmost column of an array for a particular value and returns the corresponding value from a cell in another column, indicated by the col_index_num.

VLOOKUP requires that the first column of the lookup table is sorted in ascending order. The following information describes different formulas that you can use to return the same information returned by VLOOKUP without requiring that the first column of the table be sorted.

MORE INFORMATION

Using INDEX and MATCH

The following formula return the same information that a VLOOKUP returns without requiring the first column of the table to be sorted

   =INDEX(Table_Array,MATCH(Lookup_Value,Lookup_Array,0),Col_Index_Num)

   Table_Array    = The entire lookup table

   Lookup_Value   = the value to be found in the first column of
                    "table_array"

   Lookup_Array   = the range of cells containing possible
                    lookup values

   Col_Index_Num  = the column number in "table_array" for which
                    the matching value should be returned

Using OFFSET and MATCH

The OFFSET function can be used if you are unsure of the entire address of "table_array" because it uses the MATCH function to locate the position of "lookup_value" within "lookup_array." In the following function, the "offset_col" argument uses the upper left most cell of the table as "top_cell" and returns the desired value as determined by the MATCH (offset row) and offset column:

   =OFFSET("top_cell",MATCH("lookup_value","lookup_array",0),"offset_col")

Example

   A1: Name        B1: Dept        C1: Age
   A2: Henry       B2: 501         C2: 28
   A3: Stan        B3: 201         C3: 19
   A4: Mary        B4: 101         C4: 22
   A5: Larry       B5: 301         C5: 29

   =OFFSET(A1,MATCH("Mary",A2:A5,0),2)

NOTE: In Microsoft Excel 5.0, the first column of a lookup table does not have to be sorted to use the VLOOKUP and HLOOKUP functions if you are looking for an exact match. To look for an exact match, specify the fourth argument of VLOOKUP or HLOOKUP as FALSE. If you omit the fourth argument, or specify the argument as TRUE, you must sort the first column of the table. The OFFSET function described above also works in Microsoft Excel versions 5.0, but is not necessary.

For additional information about using the VLOOKUP function to find an exact match in Microsoft Excel version 5.0, please see the following article in the Microsoft Knowledge Base:

   ARTICLE ID: Q108639
   TITLE     : XL: Range_Lookup Argument in VLOOKUP Finds Exact Match

REFERENCES

"Function Reference," version 4.0, pages 267-268, 299-300

"Function Reference," version 3.0, pages 148-149, 163-164

"Functions and Macros," version 2.1, pages 78, 320