=IF(ISBLANK(A1,"",A1*3.4%+.2)
no need for SUM function here.
Bob Umlas
Excel MVP

"owlie" wrote in message
...
Hi, I want to create a formula that only works if I have a figure in a
cell

eg.,

A1 1.70
B1 =sum(a1*3.4%)+0.20

But if A1 was blank, I don't want any figure in B1.

Thanks for any help