In order to be able to afford the monthly rent payment you need to be making 40 times your monthly income.
So if you make $50,000.00 per year the maximum amount of rent per month you can afford is $1,250.00
But you also need to factor in your other expenses and see what you'd have left after spending the $1,250.00 per month.
If possible it's best to rent an apartment or home with a little less per month than what you can actually afford if possible.