Are you wanting something like:

=if(A2="S",WORKDAY(date,3),WORKDAY(date,5))

"sue" wrote:

I am using the WORKDAY function successfully to calculate 3 days from a given
date but I would now like to extend this & perform a check whether to use 3
or 5 days depending on an input of small or lagre. Is this possible ?

s=3 days
l=5 days

=WORKDAY(date,s or l)