Its the right concept but I should have been more detailed.

The TW numbers are actually in this format

TW 0-249.9 255-461
40 .743 .752
40.5 .752 .761
41 .761 .770

So if I have 256 and 40.5 it would return .761. If I have 220 and 40 it
would return.743.

"Ron Coderre" wrote:

First, enter these numbers in Cells A1:A5
0
0.743
0.745
0.746
0.748

B1: SqFt Amount (example: 245)
B2: TW value (example: 3)
B3: =OFFSET(A1,(B1=0)*(B1<=255)*B2,0)
(in this example: B3 will equate to 0.746)

Does that give you something to work with?
--
Regards,
Ron