Melissa --
First, a minor clarification.  I think you're computing the "breakeven
point" -- the time delay until your original investment is paid for.  The
"ROI" is an interest-rate calculation -- what interest rate are you
generating on your invested money.  That said, here's one approach:

            A             B
1      Orig. Cost   $100,000
2     Yrly Return   $33,480
3
4     Breakeven    =INT(B1/B2) & " years and " & INT(MOD(B1/B2,1)*12) & "
months"

The result reads "2 years and 11 months".

HTH

Same as any other conversion from years to months: multiply by 12.

By the way, you are not calculating Return on Investment. You are
calculating the payback period (the time it takes to get your money back).

Regards,
Fred.