Operatory utilization — booked chair time over available chair time — shows how fully the practice uses its rooms. Empty chair time is fixed overhead earning nothing.
The example
34 booked of 40 available.
| A | B | |
|---|---|---|
| 1 | Item | Value |
| 2 | 34 / 40 | — |
| 3 | Utilization | → 85% |
The formula
The formula:
How it works
How it works:
- Available hours = operatories × staffed hours — the capacity you pay for.
- Divide booked clinical hours by it for utilization.
- Multiply idle hours by production per hour for the cost of empty chairs.
- Track by provider and operatory to find the slow rooms and gaps.
An empty operatory still costs full rent and staff. Utilization turns “we had a slow Tuesday” into a dollar figure: idle chair hours times production-per-hour is real lost revenue against fixed overhead. Tracking it per room and per provider reveals whether the fix is scheduling (fill the gaps), capacity (too many rooms), or demand (marketing) — each a different lever.
Try it: interactive demo
Booked, available hours, production/hr.
Variations
Idle hours
Unused chair time:
Idle cost
Lost production:
Available hours
Operatories × hours:
Pitfalls & errors
Clinical hours. Use actual treatment time, not appointment blocks if they differ.
Staffed capacity. Available = rooms staffed, not all rooms.
Zero available. Closed day gives #DIV/0!.
Practice workbook
Frequently asked questions
How do I calculate operatory utilization in Excel?
How do I value empty chair time?
How do I get available hours?
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