Are you 'pre-op' or 'post-op'? Why you shouldn't ask this question.
Transgender people are often asked this question. And we often just give the short answer just to get it over with.
But stop and think. What are you really asking? You are asking about the shape of my genitals. If someone you just met were to ask you: "How long/deep is your penis/vagina?", how would you react? You would want to hit them and haul them to jail, wouldn't you? Unless you are my doctor, or we have been dating, you have no business asking the question.
Besides, it is not a simple either-or question. For male to females, the "operation" can be three operations, Orchidectomy, Vaginoplasty, & Labiaplasty. For female to males, it can be even more complicated. You have Phalloplasty, Metoidioplasty, Metaoidioplasty, Meta, Clitoral Release, and Centurion. Then for non-genital procedures you have Chest Surgery, Peri Aureolar, Double Incision Mastectomy, Hysterectomy, Oophectomy, etc. These operations are sometimes combined, but not always. So we could be 'mid-op'. Also hormone therapy causes 'shrinkage' or 'growth' to the point that the question is somewhat meaningless.
This is not to say that some transgender people will not bring up the subject themselves. When getting the "operation" is the central focus of your life, it is hard to avoid it. When they start telling you way more about their genitals than you want to know, just humor them, and it will pass.