I don't want to appear argumentative, but in 15 years of being in gyms I have never seen somebody with visible abdominals when 15% of their total bodymass is adipose.
For the vast majority anywhere in the 10% range and under starts to look good. 7-8% looks very good in some lights, about 4-5% looks totally ripped.
Around 11-12% looks perfectly acceptable compared to your average schmoe, you won't have a gut of any kind, but you will probably only be able to see serratus and intercostals and not abs per se.
SIMES