Subtract last value from first value?

[NerdyOne]

I have a spreadsheet that is generated weekly with a presentation form in front. I need a cell to reference sheet1 and subtract the bottom value from the top value. The problem is one week there may be 4,000 records and the next week there may be 5,000 records.

So what formula could I use to subtract the last value from the top most value.

Example: =Northwest!E4392-E2 sometimes needs to be =Northwest!E5112-E2

 

[mbarron]

Try this one:
=INDEX(Northwest!E2:E65523,COUNT(Northwest!E2:E6523))-Northwest!E2

Mike

 

[NerdyOne]

Worked like a champ! Thank you very much!