So, as seen in my profile below, I'm not planning on start HRT until 2015, probably in summer sometime. (This is because my wife and I want another baby before I start, and can't really store my sperm). So, in that time, I'm learning things, preparing, etc.

My wife's entire family knows, due to the extreme negative reaction from her parents. It was never the plan, but they basically ran their mouths off about how bad I was, and now the cat's out of the bag there (they live in a different state). My closest friends know, and it's pretty much free game when I'm around them (I'll admit to it if someone they know asks). However, my family (other than parents and brother) have no idea yet. My cousins, aunts, uncles, grandparents, none of them know. I know who to expect certain reactions from, although I'm aware some people can be surprised.

My concern is my grandparents. I've got four to deal with: my paternal grandmother, who has not been in great health lately. Sadly, we don't know how much longer she will be around. It may still be many years, but she takes a lot of medication, and she can't really be left by herself for even a day. She has a live in "boyfriend." (I guess that's what we call him. lol). My dad is concerned telling her will deteriorate her health faster.

My maternal grandmother is very religious. Goes to church every Sunday, very involved in church functions, and VERY judgmental. She didn't want my mom to marry my dad. I am not expecting a good reaction from her, so I believe I will already be into my HRT when I tell her (aka "I can't stop now Nana. I'm already into it).

My maternal grandfather and step-grandmother are semi-open minded. My grandfather can be... stern? I'm not sure what to expect of them. I'm not sure they'll understand.

I guess my question is how other peoples' grandparents reacted to things, and what you think of how my grandparents will react, or if I should even tell them. I don't want to never see them again (my dad already has that relationship with my maternal grandmother), but I know that older people "never had to deal with this stuff" and will probably be confused and possibly unsupportive.

P.S. I also have two other people who are like grandparents to me. I met them when I was in high school, and they taught me about taking care of horses. I see them once in a while, but I think they will be a bit more understanding because her son is gay. (They are married but each have children from previous marriages).

My dad's parents were dead before I was born, and I'm fairly certain my mom's parents would find ways to be nasty whether I transitioned or not. I don't talk to them and don't know how they feel.

I don't think you should tell your grandparents anything. If you are like most humans, word will spread like wildfire and they'll figure it out on their own.

My grandmother is a very devout Catholic and can be judgmental at times, yet be surprisingly cool others times.  She very much believe(d) in strict traditional gender roles, racist and conservative yet she was pro same-sex marriage when it was a major topic here in Canada a few years ago.

Now she accepts me as being trans and even supports my transition, but yet I get the felling she doesn't accept me as her granddaughter.  It hurts a bit but the situation could be much worse.

My grandfather was again a devout Catholic and a firm believer in strict gender roles. He was the one who always would tell me that "boys/men don't do x" when I was growing up.  He also has a prejudice side to him, but also is very "live and let live" when it comes to sexuality.  Again he supports me in my transition. His only objection was my name change.  I was named after him, but his tune changed after I told him that I was using a feminine version of my birth name as my new middle name.  Again he's had a tough time adjusting.  He get the pronouns wrong 95% of the time! but genuinely feels bad when he realizes it.

Both are 85 years old and both have made it clear that they still love me.  They even gave me $20k to have some major dental work done and offered to pay for my SRS if it wasn't already paid for by the government.