VLOOKUP function
Searches for a value in the leftmost column of a table, and then returns a value in the same row from a column that you specify in the table. Use VLOOKUP instead of HLOOKUP when your comparison values are located in a column to the left of the data you want to find.
The V in VLOOKUP stands for "Vertical."
Syntax
VLOOKUP (lookup_value,table_array,col_index_num, range_lookup )
Argument 
Description 
Remarks 
lookup_value 
The value to be found in the first column of the array. The lookup_value argument can be a value, a reference, or a text string. 

table_array 
The table of information in which data is looked up. You can use a reference to a range or a range name. 

col_index_num 
The column number in table_array from which the matching value must be returned. 

range_lookup 
A logical value that specifies whether you want this function to find an exact match or an approximate match. 

Example
The example uses values for air at 1 atm pressure.
To make the following example easier to understand, you can copy the data to a blank sheet and then enter the function underneath the data. Do not select the row or column headings (1, 2, 3... A, B, C...) when you copy the sample data to a blank sheet.
Density 
Viscosity 
Temperature 
0.457 
3.55 
500 
0.525 
3.25 
400 
0.616 
2.93 
300 
0.675 
2.75 
250 
0.746 
2.57 
200 
0.835 
2.38 
150 
0.946 
2.17 
100 
1.09 
1.95 
50 
1.29 
1.71 
0 
Formula 
Description (Result) 

=VLOOKUP (0.946,A2:C10,2) 
Looks up 0.946 in column A, and returns the value from column B in the same row. (2.17) 

=VLOOKUP (1,A2:C10,3, TRUE ) 
Looks up 1 in column A, matches the next smallest value (0.946), and returns the value from column C in the same row. (100) 

=VLOOKUP (.7,A2:C10,3, FALSE ) 
Looks up 0.7 in column A. Because there is no exact match in column A, an error is returned. (#N/A) 

=VLOOKUP (0.1,A2:C10,2, TRUE ) 
Looks up 0.1 in column A. Because 0.1 is less than the smallest value in column A, an error is returned. (#N/A) 

=VLOOKUP (2,A2:C10,2, TRUE ) 
Looks up 2 in column A, matches the next smallest value (1.29), and returns the value from column B in the same row. (1.71) 