Sales per labour hour: what it shows and what it cannot prove

Sales per labour hour divides sales in a period by labour hours in that same period. It describes an observed relationship. On its own, it cannot tell you the right staffing level, establish that staffing caused sales, or predict the result of removing a worker.

A worked example

A synthetic shop records £600 of net sales during two hours. Three people are rostered for that whole period, giving 6 rostered labour hours. Sales per rostered labour hour is £600 divided by 6, or £100.

Use rostered labour hours when the source is a roster. Do not present them as paid or actually worked hours unless that is what the source records. A person covering only part of the period contributes only those overlapping hours.

Compare like with like

• Use the same site, currency and sales basis, such as net sales.
• Align sales intervals and shift times in the correct time zone.
• Check that daily totals have not been treated as hourly observations.
• Account for missing sales periods and missing roster rows.
• Investigate opening, closing, preparation, breaks and other non-selling work.

When labour hours are zero, the ratio is undefined; do not display it as zero or infinity. A low ratio may reflect essential preparation or a quiet trading period. A high ratio may reflect strong demand, missing staff records or pressure on the team. Both need context.

What a staffing scenario means

Holding the example’s £600 of historical sales fixed while reducing the denominator to 4 hours produces a mathematical ratio of £150. That arithmetic does not establish that the shop could have achieved the same sales with fewer hours, or maintained the required service.

Before making a change, review coverage, skills, breaks and workforce risk. Fewer rostered hours become a cash saving only when the actual pay arrangement and operational change support that conclusion. Do not treat a ratio improvement as a realised benefit.

Where RosterWise helps

On Business Pro and Enterprise, roster and sales data can be reviewed together. Observed patterns help identify periods worth investigating; proposed changes are compared with the available evidence and supplied constraints before a person decides.

See Business Pro, the roster change checklist and what the checks can establish.