I have the formula listed below which at times will produce #VALUE due to the cells in Col D not being populated yet.

=IF(O3 < 1500, (D3/4) * 0.008, (D3/4) * 0.004)

I want to add ISERROR in this to show 0 if the cell in D is not filled in, I tried this

=IF(ISERROR(O3 < 1500, (D3/4) * 0.008, (D3/4) * 0.004), 0)

I get an error stating too many arguments, clicking OK highlights the 0.008 section of the formula.

Can someone please tell me where I am incorrect in this formula?