With cost in A1, salvage in A2, number of periods in A3, the following array
formula worked for me to calculate the sum of periods 1-5. You must enter this
formula with CTRL+SHIFT+ENTER.

=SUM(SYD(A1,A2,A3,{1,2,3,4,5}))


On Fri, 29 Oct 2004 00:48:03 -0700, "Guey Lan" <Guey
wrote:

I am using SYD to calculate hire purchase interest using "Sum of Digit"
method. That function have no problem in calculating monthly interest, the
problem I am facing is the principal amount owing within 12 months (calculate
in one cell).
Please advise!!