Chair Utilization
Definition, formula, a worked example, and the mistakes that make it wrong. For infusion centers.
What is chair utilization?
Formula
(Completed infusions × average chair time) ÷ (chairs × operating hours a day × operating days)
What each part means
- Completed infusions
- Visits where the patient came and drug was given. Scheduled visits minus no-shows and same-day cancellations.
- Average chair time
- Door to door, from the moment the patient sits down until they leave: vitals, pre-medication, the infusion itself, and observation. Not just the run time on the order.
- Chairs
- The chairs you can staff, not every chair in the room.
- Operating hours and days
- From the first chair start to the last checkout, on the days the center runs infusions. Use each site's own hours and local time.
Worked example
A site has 10 chairs open 8 hours a day, 5 days a week: 10 × 8 × 5 = 400 available chair-hours. It completes 120 infusions a week at an average of 2.5 hours each, which uses 300 chair-hours. Chair utilization is 300 ÷ 400 = 75%.
Run your own numbers: Infusion chair utilization calculatorWhere the numbers come from
- Appointment list from your infusion software: status, location, chair, scheduled start and end
- A table you keep of chairs and open hours for each site
- A spot-check of a few days against what happened on the floor
Mistakes that make it wrong
- Counting the schedule instead of completed visits
- No-shows, same-day cancellations, and visits moved for a lapsed authorization make utilization look higher than what happened on the floor.
- Using drug run time instead of chair time
- The order may say 30 minutes while the patient sits for 90 once vitals, pre-medication, and observation are counted.
- Counting booked visits that never happened
- Most infusion software stores scheduled start and end times, not when the patient left the chair. If that is all you have, use the scheduled length of each completed visit, and never count booked visits that did not happen.
- Averaging across sites or hours
- A full site and a half-empty one average out to fine. Add up chair-hours across sites and divide by total available chair-hours, and look by weekday and hour too.
What good looks like
There is no published standard we could verify for infusion centers. The right target depends on your staffing, your mix of short and long infusions, and how much room you keep for add-ons. Measure your own baseline for a quarter, then set a target you can staff.
Common questions
How do you calculate infusion chair utilization?
Divide the chair-hours patients used (completed infusions times average door-to-door chair time) by the chair-hours available (chairs times operating hours a day times operating days a week).
Do no-shows count toward chair utilization?
Not in our calculator. It counts only completed infusions, because a chair held for a patient who never comes is empty.
Should chair time include pre-medication and observation?
Yes. The chair is unavailable from the moment the patient sits down until they leave, so use door-to-door time.
How do you roll up chair utilization across several sites?
Add the used chair-hours across sites and divide by the added available chair-hours. Averaging site percentages gives a small site the same weight as a large one.
What limits infusion capacity besides chairs?
Nurse-to-chair ratios, pharmacy prep time, and a few very long infusions often bind before chairs do. If utilization is below target but the floor feels full, check those first.
Want chair utilization from your own data?
We build the reports that calculate it the same way every month, from the systems you already use.