How to use this calculator
- Enter or choose patients on the unit.
- Enter or choose nurses on duty.
- Enter or choose target patients per nurse.
- The nurses needed for the target updates as you type. Use Copy result or Share to keep it.
Method
Patients per nurse = Patients ÷ Nurses; Nurses needed = ⌈Patients ÷ Target patients per nurse⌉; Shortfall = max(0, Nurses needed − Nurses on duty)
- Patients
- patients on the unit for the shift
- Nurses
- nurses with a patient assignment (exclude the charge nurse if they take no patients)
- Target
- maximum patients per nurse under your policy
Worked example
- Current load = 26 ÷ 5 = 5.2 patients per nurse.
- For a 1:4 target, 26 ÷ 4 = 6.5, rounded up to 7 nurses.
- Shortfall = 7 − 5 = 2 nurses.
Twenty-six patients with five nurses is a 1 : 5.2 ratio; meeting a 1:4 target needs seven nurses, two more than on duty.
What the result means
The ratio is a floor, not the whole picture: patient acuity, skill mix and unit layout also determine safe staffing. Use the result to flag shifts that miss the target, then apply your acuity tool.
Assumptions and limits
- Every nurse counted takes a full patient assignment.
- The target ratio is the one you enter; no legal ratio is built in.
- Does not account for acuity, admissions and discharges during the shift, or breaks.
Questions
Are nurse-to-patient ratios set by law?
In some places, for some units. Requirements differ widely, so check your regulator or hospital policy and enter that figure as the target.
Why round up?
You cannot roster half a nurse, so meeting the target needs the next whole number.