It varies by hospital, floor, acuity, etc. When I worked in the hospital, ratios on my floor were typically 3:1 on days and 4-5:1 on nights. We occasionally had high acuity patients who should have been in the ICU but were admitted to the floor's pretend "step-up" unit because they wanted the patient on the specialty floor. Those patients were meant to be 2:1 at all times but, if staffing didn't allow for it, it didn't happen. I've taken assignments with up to 5 patients when I was supposed to have 2, others have had to go to 6.