=IFERROR(F45/F45+G45),"N/A") will work if you're using Excel 2007 or later..

Well, I tried it and got:

You've entered too few arguments for this function.

To get help help with this function, click ok to close message. Then click the Insert Function button.

I do this but am not sure what to add in the IFERROR spot.

Sorry, my bad. I was typing the reply on my phone and missed a bracket.

Try =IFERROR((F45/F45+G45),"N/A")

Thanks for the help so far.

That worked to put "N/A" in the field but removes my calculation into a percentage. So when my total equals 0 I get "N/A." But when I actually have a number in F45 or G45 it just adds them up instead of dividing them.

Ex: F45 has 1 and G45 has 1 I get 200% instead of 50%.

The formula you put in your original post (=F45/F45+G45) would also give you 200% and not 50%.....

I'm not sure I understand what you're trying to achieve with this.
Dividing the value in F45 by F45, as in the first part of your formula, will always give you 1 unless F45 contains zero to start with.

Perhaps if you could explain a little more about what you're trying to achieve it would be possible to get the right formula for you.

Ok, I am sorry.

Here is the formula I am using to get my percentage of two columns:

=F45/(F45+G45) <-----I missed one ( here when typing it. Sorry.

I get the right percentage of the total columns. If F45 = 1 and G45 = 0 I get 50%. That all works fine.

But some of the columns will not have numbers to calculate. If F45 and G45 total zero I get the DIV error.

I need to get the percentage to display or have N/A display if the total is zero.

Then you just need to wrap the IFERROR around the formula you have above.
=IFERROR(F45/(F45+G45),"N/A")

Does that do the trick?