A nursing facility needs nurses around the clock, but how many are required? The industry standard for calculating nursing hours is finding a facility's nursing hours per patient day. This equation can accurately determine nursing hours in relation to individual patients and allow nursing facilities to properly staff themselves with an adequate number of nurses.

Add the total number of workers in a nursing facility in a 24-hour period. According to the Texas Association of Homes and Services for the Aging, this should only include nurses and staff directly engaged in patient care, including charge nurses, medication aides and nursing assistants. Multiply this number by the shift hours to calculate total labor hours of direct care workers.

Add the total number of part-time direct care workers in a 24-hour period and, as before, multiply this number for the hours worked.

Add the total number of full- and part-time totals from the first two steps. This total number should be divided by the facility's number of patients present in the facility during duty hours. For example, a nursing facility with 10 patients manned by two nurses working eight hours each provides 1.6 nurse staffing hours per patient day.

The total in this equation provides the nursing hours per patient day, which helps nursing facilities understand what ratio of nurses to patients is best for them. For all licensed facilities nationwide, the average total nursing staff hours per patient day was 4.0 for January 2011 through February 2012, according to the Kaiser Family Foundation,. The average licensed nurse hours came to 1.6 per patient day.