I am in the same situation, and I think there is different way to approach the problem, first if you have a particular reasoning as to why you do not want children, then explain it to them. People are more encline to accept your choice if you a "solid" reason for that choice (while you should'nt have to explain your life choices to anyone).

If there is no particular reason behind it, apart from the fact that you don't want to be a parent (wich should be reason enough), you could go with argument like :

I don't want to selfishly bring a child in a world like ours.

It's pretty hard to argue against that, and most people will likely leave it at that.

I want to be able to focus on my carreer.

Depending on your job, this might be a perfect argument, most people know that some job are not really compatible with having a family.

I don't feel ready to be a parent just yet.

This will most likely work on most people because it's not a definitive statement, there's still the possibility of having a child one day.

If a person is really annoying about this, I usually tell them that my life choices are mine alone and that they should leave it at that.

But you need to be aware that, in western society having a child of your own is "the norm" (the inability to conceive was one of the argument provided against gay marriage). When you don't want children of your own people will find it weird, no matter what.

I am in the same situation, and I think there is a different way to approach the problem, first if you have a particular reasoning as to why you do not want children, then explain it to them. People are more inclined to accept your choice if you offer a "solid" reason for that choice (while you actually shouldn't have to explain your life choices to anyone).

If there is no particular reason behind it, apart from the fact that you don't want to be a parent (which should be reason enough), you could go with an argument like :

I don't want to selfishly bring a child into a world like ours.

It's pretty hard to argue against that, and most people will likely leave it at that.

I want to be able to focus on my career.

Depending on your job, this might be a perfect argument, most people know that some jobs are not really compatible with having a family.

I don't feel ready to be a parent just yet.

This will most likely work for most people because it's not a definitive statement, there's still the possibility of having a child one day.

If a person is really annoying about this, I usually tell them that my life choices are mine alone and that they should leave it at that.

But you need to be aware that, in western society having a child of your own is "the norm" (the inability to conceive was one of the arguments provided against gay marriage). When you don't want children of your own people will find it weird, no matter what.