Formula Help

[Zach1370]

I need help writing a formula in column L.  The calculation for L4 is simply the sum of J4=K4.  My question is what formula can I use in L column that will only use the K4 result if J4 is blank?  Then if J4 has a value, the L column would go back to the sum of J4 and K4.  You can see that I couldn't figure out how to sum the values in L5 and the result shows up as FALSE.

[#2]

@Zach1370 

Simply use

=SUM(J4:K4)

Then fill down.

The SUM function ignores blank cells, so if column J is blank, SUM will return the value from column K only.