Calculate shift hours including overnight shifts and rotation coverage.
Overnight shifts must wrap past midnight, otherwise the span comes out negative. Multiplying by shifts and staff gives the total hours a rota consumes, which is the rostering figure. Naive subtraction producing negative hours for night shifts is the single most common rostering software bug.
Shift Hours
Shift hours = clock span − unpaid break, wrapping past midnight when needed
Shift hours = clock span − unpaid break, wrapping past midnight when needed Overnight shifts must wrap past midnight, otherwise the span comes out negative. Multiplying by shifts and staff gives the total hours a rota consumes, which is the rostering figure.
Naive subtraction producing negative hours for night shifts is the single most common rostering software bug.
This calculator takes 5 inputs: Shift start, Shift end, Unpaid break, Shifts per week, Staff per shift. The pre-filled defaults are a realistic starting point — replace them with figures from your own environment for a result you can act on.