Enter admission and discharge dates to get the length of stay by the midnight-count convention hospitals and payers use.
How LOS is counted
Length of stay sounds trivial until two systems disagree by a day — which happens whenever one counts calendar days and the other counts midnights. The standard convention is the midnight count: discharge date minus admission date, so the admission night counts and the discharge day doesn’t. Enter both dates and this calculator applies it, with the same-day edge case handled the way averages conventionally do.
How to use it
- Enter the admission date.
- Enter the discharge date.
- Read the LOS — the midnight count both DRG analysis and utilization review expect.
The rule
A worked example
Admitted 10 August, discharged 14 August: 4 days — four midnights, even though the patient was present on five calendar dates. Multiply across a service line and the convention matters: average LOS against the DRG’s expected stay (the geometric mean) is how utilization review spots outliers in both directions — stays running long, and the discharge pressure running too short.
Estimates only — payer contracts, plan documents, published fee schedules and the EOB are the source of truth, and nothing here is billing, legal or medical advice. The calculator runs entirely in your browser: no patient data is entered, transmitted or stored.