Roster Size Calculator

Convert a weekly staff-hour requirement into a practical roster size.

How to use the Roster Size Calculator

1. Provide weekly coverage hours, productive weekly hours per employee and reserve percentage using one consistent planning period.
2. Confirm whether the reserve percentage already includes leave, training and expected absence.
3. Calculate the result to estimate base and reserve-adjusted roster size.
4. When reviewing the output, watch for adding the same relief allowance twice in different inputs.

What this calculator does

Convert a weekly staff-hour requirement into a practical roster size. Only the values entered on the page are used to estimate base and reserve-adjusted roster size.

The result is a planning estimate based on numerical coverage assumptions. Operational requirements such as qualifications, post restrictions, supervision and simultaneous demand may increase the real requirement.

Roster size and simultaneous on-duty staff are different

A roster may need many more people than the number physically on duty at one moment because coverage is spread across shifts, rest days and absences. Use productive hours and reserve assumptions to translate coverage demand into a total team size.

Calculation example

For a real record, replace every sample value with your own data and verify whether the reserve percentage already includes leave, training and expected absence.

How to interpret the result

In particular, confirm whether the reserve percentage already includes leave, training and expected absence and avoid adding the same relief allowance twice in different inputs.

Practical checks before using the result

• Verify the key assumption: whether the reserve percentage already includes leave, training and expected absence.
• Avoid a common error: adding the same relief allowance twice in different inputs.

Calculation design and testing notes are documented in the Calculator Methodology and Accuracy Policy.

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