Spoke too soon ? They both work to a point. IF the figure comes out at 1.5 it should display 1.5 as this is a round up length. However when it runs in the statement
=IF(A1<=3,LOOKUP(A1,{0,0.5,1,1.5,2,2.5,3},{0.5,1,1 .5,2,2.5,3,3}),ROUNDUP(A1,0)) if the return figure is 1.5 it rounds up to the figure 2 where as it should display 1.5 any ideas as to the solution

=CEILING(A1+0.0000000000001,0.5+0.5*(A1>=3)) returns the same set of figures however once you get a result say 3 it rounds up to four however it should display 3 as it is a round up figure

Nearly solved