The Building Officials and Code Administrators handbook states that for health and safety reasons you need 70 square feet of bedroom space for one occupant. If you have more than one occupant you need 50 square feet per person.

If you have a unit with one-bedroom that measures 10 x 8 or 80 square feet it would be too small for two people.

But if you have a unit with one-bedroom that measures 10 x 16 it may be big enough for three people.