Stay at home mom?

This is somewhat of a personal question so obviously only answer if serious, but for a family of soon to be 3, how much do you think is comfortable for your spouse to make for you to become a stay at home mom. Would you quit your job if you were just getting by? Etc. my husband and I want my self to take a year off and stay at home, but we are unsure of what would be suitable to do this. I'm going to post this anonymously because I know someone will say this is stupid but I'm seriously unsure. Thanks!!