Should I come out to my parents as being an atheist?

The short answer is "No."

The slightly longer answer is that if you are not in a position where that is likely to end well for you, you should probably wait until you're more self-sufficient. However, you know your own parents better than we do. You could try breaking the ice on the subject of atheism to get a feel for their reaction to it in general, if you're not sure. Always keep in mind that for many people religion is a highly emotive subject, and for many parents who have been raised to believe in the "moral superiority" of religious belief, a child who comes out as an atheist can be interpreted as a betrayal of them or as a failure of their own.

In some religions, it can actually be dangerous to "out" yourself. If your father is a hardline Muslim, for example, getting kicked out of the house is the least of your worries. You risk being beheaded or set on fire. If you're coming from one of those, keep that in mind as well.

/r/atheism will almost invariably respond that you should wait. A common proverb here is "The best place to come out to your parents is at a home you own, over a dinner that you paid for yourself".

If you do decide to "come out," then consider that "atheist" has many evil, hateful connotations to religious people. It's right up there with "Satanist." You might be able to reduce the amount of flak you get by choosing a label for yourself that has a similar meaning but is less controversial. Please consider using an alternative such as "agnostic" or "humanist", which does not carry quite as much baggage.

There's also another approach: You could say "I've lost my belief" or "I don't know what to believe any more" or even "God doesn't speak to me any more." Asked if you are an atheist, you could say "I don't know."

This makes you look less like a monster and more like a victim. You'll be subject to sympathy rather than anger. You won't be kicked out. But you run the risk of having folks work really hard to bring you back to God. Expect (more) frequent church visits, and maybe a talk with the priest/pastor/counsellor.