What Is ALOS (Average Length of Stay)?
The formula, worked examples, what counts as a healthy figure for your property type, and why a longer average stay lowers your cost per booking more than almost anything else you can change.
ALOS Definition and Formula
ALOS stands for Average Length of Stay. It measures the average number of nights a guest stays per booking, and it is calculated by dividing the total occupied room nights in a period by the total number of bookings in that same period. An ALOS of 2.4 means the typical reservation at your property covers just under two and a half nights.
The Formula
ALOS = Total occupied room nights ÷ Total number of bookings
Both figures must cover the same period and the same set of rooms. The most common mistake is mixing a room-nights figure that includes complimentary or house-use rooms with a bookings count that does not — which quietly inflates the result.
Worked Examples
The spread across those four rows is the point. ALOS is almost meaningless as an absolute number and very informative as a trend against your own history and your own segment.
Why ALOS Matters More Than It Looks
Every booking carries a fixed cost. A longer stay spreads it over more nights.
A reservation has costs that do not change with its length: the commission on the booking, the payment processing, the check-in, the arrival clean and setup, the departure clean, the administrative handling. Whether the guest stays one night or five, most of that is incurred once.
So two properties selling the same number of room nights at the same rate can have materially different margins. Ten bookings of one night each require ten arrivals, ten departures, ten full turnovers and ten commissions. Two bookings of five nights require two of each. The revenue line is identical; the cost line is not remotely.
This is why ALOS deserves a place next to occupancy and ADR rather than being treated as a curiosity. Raising ALOS from 1.8 to 2.2 nights reduces the number of bookings needed for the same occupancy by roughly 18%, and with it the commission, the turnovers and the front desk load.
How ALOS Relates to the Other Metrics
- Occupancy tells you how much of your capacity sold. ALOS tells you how efficiently it sold — in a few long bookings or many short ones.
- ADR tells you the average rate per night. A rising ALOS often comes with a slightly lower ADR, because longer stays are usually discounted, so the two should be read together.
- RevPAR combines rate and occupancy but is blind to stay length, which means it cannot see a margin problem caused by high turnover.
- Cost per occupied room is where ALOS shows up most visibly. If it is falling while occupancy holds steady, a rising ALOS is usually the reason.
What a Healthy ALOS Looks Like
There is no universal target. Compare against your segment and your own trend.
Treat those as orientation rather than benchmarks. The useful question is never "is 2.3 good" — it is whether your ALOS is rising or falling against the same month last year, and whether the mix causing the change is the mix you want.
Watch the distribution as well as the average. A property with an ALOS of 3.0 made up of many one-night stays and a handful of two-week stays is operationally very different from one where nearly every booking is three nights, even though the metric reads identically.
How to Increase ALOS
Five levers, roughly in order of how quickly they take effect.
- Price the extra night deliberately. A modest discount on nights three and beyond converts a meaningful share of two-night bookings into three-night ones, and the margin usually improves despite the lower nightly rate because you have avoided an entire turnover.
- Use minimum-stay restrictions on high-demand dates. If a Saturday sells out regardless, requiring two nights over the weekend protects you from being left with an unsellable orphan Friday or Sunday.
- Close the gaps in your calendar. Single empty nights between bookings are the most expensive inventory you own. Rate rules that price a one-night gap attractively, or allow it to be filled at short notice, recover nights that would otherwise go empty.
- Sell the destination, not just the room. Guests extend when there is a reason to. Concrete, specific content about what to do on a third day converts better than a generic discount, and costs nothing per booking.
- Ask at the right moment. A well-timed offer to extend, made during the stay rather than at checkout, catches guests while they are still deciding — and costs nothing if declined.
Track the effect on ALOS and cost per occupied room together. A lever that raises ALOS while pushing ADR down more than proportionally is not a win, and you will only see that if you are reading both.
Frequently Asked Questions
What does ALOS stand for?
ALOS stands for Average Length of Stay. It is a hotel performance metric measuring the average number of nights a guest stays per booking, and it sits alongside occupancy, ADR and RevPAR in standard hotel reporting.
How do you calculate average length of stay?
Divide the total occupied room nights in a period by the total number of bookings in the same period. For example, 412 room nights across 196 bookings gives an ALOS of 2.10 nights. Both figures must cover the same period and the same set of rooms — including complimentary rooms in one figure but not the other is the most common source of error.
What is a good average length of stay for a hotel?
It depends entirely on property type. Airport hotels sit close to 1 night, city business hotels around 1.5 to 2.5, boutique and leisure properties around 2 to 4, resorts around 4 to 7, and serviced apartments a week or more. Rather than chasing an absolute number, compare your ALOS against the same period last year and against your own segment.
Why is ALOS important?
Because a large share of the cost of a booking is incurred once regardless of its length — commission, payment processing, check-in, arrival and departure cleans, administration. Ten one-night bookings cost far more to service than two five-night bookings producing the same room nights and revenue. Raising ALOS lowers your cost per occupied room without needing a single extra booking.
How can a hotel increase its average length of stay?
The most effective levers are discounting the third night and beyond so two-night bookings extend, applying minimum-stay restrictions on high-demand dates, using rate rules to fill single-night gaps between bookings, publishing specific content that gives guests a reason to stay another day, and offering an extension during the stay rather than at checkout.
What is the difference between ALOS and occupancy rate?
Occupancy rate measures what share of your available rooms sold over a period. ALOS measures how those room nights were distributed across bookings. Two hotels can run identical occupancy with very different ALOS — one through many short stays, the other through fewer long ones — and the second will almost always have lower costs per occupied room.
See ALOS Alongside Every Other Number
Frontdesko reports length of stay next to occupancy, ADR and RevPAR from your live data — no spreadsheet, and free forever.
Related Guides
The rest of the hotel metrics glossary
What Is RevPAR?
Revenue per available room — the headline metric, its formula and what moves it.
Learn More →What Is ADR?
Average daily rate explained, with worked examples and common mistakes.
Learn More →What Is Occupancy Rate?
How occupancy is calculated and why the denominator matters more than people think.
Learn More →