Thanks for having such a great forum. I spent some time reading other threads on this forum. I really enjoy reading your replies.

I find that you usually estimate the risk of HIV infection following a single unprotected sex as around 1/2500, and using a condom reduces the risk to 1/250000. You also claim that being uncircumcised roughly doubles the risk. 

I am uncircumcised, and I can't judge if I have a long foreskin or not. Let's assume that I have a long foreskin, so I don't know if a condom can cover my entire foreskin when my penis is erect during sex.

My questions are:

Does being uncircumcised affect condom protection? Even if I am uncircumcised, can I still assume that a condom gives 99% protection against HIV? In particular, for myself, the risk of HIV infection following a single unprotected sex is 1/125000. Do you agree with my calculation?

Thanks very much for your time.

There are no scientific data quantifying foreskin lenght/size and how that related to risk for HIV, if exposure.  The same is true related to variables such as penis size.  Similarly, there are no data on the interaction of the presence or absence of the foreskin and condom protection however, the mechanism by which condoms work, i.e. providing a barrier between mucosal surfaces, would be expected to be similar whether one is circumcizer or not.  When properly used however, a condom would completely cover the foreskin.  

Calculated estimates of risk per sex act and levels or protection provided by condoms are average estimates which might be modified in small ways by numerous variables but nonetheless do provide a general means of estimating risk.  I would assume that when used correctly from the beginning to end of an exposure, I would expect virtually complete protection with use of a condom.  

I hope this perspective is helpful.  EWH

I learned that being uncircumcised increases HIV risks because the inner surface of the foreskin (the space between the head of penis and foreskin) is susceptible, but the outer surface of the foreskin is no more susceptible than the penis shaft. Am I right? If so, then as long as the condom covers the inner surface of my foreskin, the protection is considered complete, just like putting a condom on a circumcised penis. Do you think my thoughts are reasonable? 

In general, when I use a condom, my worry is that the condom does not cover my entire penis, and the outer surface of my foreskin (when it is retracted) may not be fully covered during sex. Certainly, the head of my penis, my urethral opening and the inner surface of my foreskin are covered. In this case, do you still think that my protection is complete?

I am looking forward to your comments.

I would have confidence that the condom would cover the critical areas of the oenis.  It is not uncommon that condoms do not cover the entire shaft of the penis but this does not reduce their effectiveness.  

Hope this helps.  One remaining follow-up.  EWH