You're using tabular data in calculations and you need an easy way to look up values in the table for use in other calculations.
Use the built-in functions
Excel provides five functions to help you access data in tabular form. These functions come in handy when performing calculations that require looking up data from standard tables. For example, you can develop a spreadsheet to perform thermodynamic calculations and include standard steam tables in this spreadsheet. This way, instead of manually looking up fluid properties to use in your calculations, you can automatically include that data via the lookup functions discussed here.
The syntax for
Lookup finds the value in
result vector corresponding to the position of the value in
lookup vector that matches
lookup value. The lookup vector must be sorted in ascending order (see Recipe 3.9). Also, the lookup and result vectors may be row or column ranges.
You can use text or a number as the lookup value; the function just compares the lookup value to the data stored in the lookup vector to find a match. This is an important caveat with this function (and the others discussed here), as no interpolation is performed. The function looks for an exact match and if it does not find one, it returns the value in the result vector corresponding to the value in the lookup ...