OR Utilization Calculator
Calculate the efficiency of your operating theatre schedules.
Standard block time allocated (e.g., 8am to 4pm is 8 hours).
Enter 1 for a daily view, 5 for weekly, or 20 for monthly.
Cumulative time from 'Wheels In' to 'Wheels Out'.
Cumulative cleaning and setup time between cases.
Utilization Rate
0%
Total Available Capacity:
0 min
Total Utilized Time:
0 min
Unused / Idle Time:
0 min
How to Calculate Operating Theatre Utilization Rate
Operating Theatre (OR) utilization is a critical Key Performance Indicator (KPI) for hospital administration. It measures how effectively the allocated surgical block time is being used. High utilization indicates efficient scheduling and resource management, while low utilization suggests wasted resources and higher overhead costs per case.
The Utilization Formula
The standard formula for calculating raw utilization involves comparing the time the theatre was used against the time it was staffed and available.
Utilization Rate (%) = (Total Utilized Time ÷ Total Available Time) × 100
1. Calculating Total Available Time
This is the denominator of the equation. It represents the maximum potential capacity based on staffing.
- Formula: (Number of ORs) × (Staffed Hours per Day) × (60 minutes) × (Number of Days)
- Example: 5 ORs staffed for 8 hours each over a 20-day month = 5 × 8 × 60 × 20 = 48,000 available minutes.
2. Calculating Total Utilized Time
This is the numerator. Definitions can vary slightly by institution, but generally, it includes:
- Surgical Time (Wheels In to Wheels Out): The actual duration the patient is in the room.
- Turnover Time: The time required to clean the room and set up for the next patient. (Note: Some strict definitions exclude turnover, but operational efficiency models usually include it as necessary "used" time).
Interpreting the Results
Once you have calculated the percentage, you need to interpret what it means for your surgical department.
| Utilization Rate | Status | Implication |
|---|---|---|
| < 75% | Under-utilized | Staff and facilities are idle too often. Consider consolidating schedules or closing blocks. |
| 75% – 85% | Optimal | Ideally balanced. Efficient use of resources with enough buffer for emergencies or overruns. |
| > 85% | Over-utilized | High risk of staff burnout, delays, and cancellations due to lack of buffer time. |
Why Turnover Time Matters
Turnover time is often the "hidden killer" of utilization rates. If a surgeon performs 5 cases a day, and the turnover time averages 40 minutes instead of a target 20 minutes, that is 100 minutes (1 hour 40 minutes) of lost surgical opportunity per room, per day.
Strategies to Improve Utilization
- Accurate Case Duration Estimates: Use historical data rather than surgeon estimates to book accurate block times.
- First Case On-Time Starts: Delays in the first case of the day ripple through the entire schedule.
- Parallel Processing: Induce anesthesia in a dedicated induction room while the OR is being cleaned to reduce turnover time.