Put a '$' character before the row number and/or column letter that you want
Excel NOT to change as you copy down. E,g,

=SUM(A1*$E$1)*0.15

See http://www.cpearson.com/Excel/relative.aspx for details.


--
Cordially,
Chip Pearson
Microsoft MVP - Excel
Pearson Software Consulting
www.cpearson.com
(email on the web site)

"vcff" wrote in message
...
Hi all

E1:20

A1:1 B1:=sum(A1*E1)*0.15
A2:2 B2:=sum(A2*E1)*0.15
A3:3 B3
A4:4 B4
A5:5 B5
..
.

I will like to copy the formula in B1 down to B50 and more in future but
how
do I ensure that only A1 will change as I copy downwards but the E1 will
remain as a fixed reference cell in the formula?

I will change the figure in cell E1 as and when needed.
.
.
.