Understanding Average Length of Stay
How we calculate. ALOS (days) = total inpatient patient-days ÷ discharges. The form uses the same arithmetic as the worked examples on this page. See our methodology and accuracy policy.
Real-world scenario: A typical Average Length of Stay case uses patient days 2400 and discharges 400. Enter the same figures below to reproduce the worked path.
What is Average Length of Stay?
Capacity and care-efficiency KPI. Day-count rules (admission/discharge day) follow facility policy.
- Patient days = sum of inpatient days
- Same discharge set in the denominator
- Segment by DRG/service for fair compares
The Formula
Worked Example
Common Use Cases
- Capacity planning: bed demand
- Case management: outlier reviews
- Service-line dashboards: efficiency
Pro Tips
- Watch observation status rules
- Exclude newborns if policy requires
- Pair with occupancy
Limitations: Average Length of Stay results are Educational operations/planning aids only—not medical, clinical, billing, or regulatory advice. Confirm definitions with your facility policies and clinicians.
FAQ
Calendar days or midnights?
Follow your census/patient-day definition—often midnight census days.
What if discharges is 0?
ALOS is undefined—check discharge counts.
Authoritative References
For healthcare quality and operations definitions, consult:
- CMS — U.S. quality and payment measure context
- WHO — global health indicator concepts
- The Joint Commission — accreditation and safety frameworks