Guide · Updated October 2026
Occupancy monitoring: how to track how many people are inside, in real time
Occupancy monitoring tells you how many people are inside right now. A counter at each entrance records everyone coming in and going out; the difference is your live occupancy, on a phone, a dashboard or a screen at the door, with an alert before you reach your limit.
City Library · all entrances Live
86 inside · capacity 120
72% fullAlert at 110
In short
Occupancy is entries minus exits since you opened. You can keep it by hand at the door, with a clicker or an app, or automatically with a counter at each entrance. For a live number you can trust all day, both directions must be counted accurately — which is why we recommend a ceiling-mounted 3D counter, the 3D SCOPE II LC, with the T.M.A.S. Real-Time plan: live occupancy, capacity alerts, a live entrance screen (Screenlet) and reports, for one location or many.
Why it matters
What a live occupancy number is for
Stay under your capacity
Keep every hour under the limit on your occupancy permit, with a timestamped record to show if anyone asks.
Staff for the crowd you have
Peaks show up as they happen, not in next week’s report, so you can open a register or another door in time.
Shorter lines, calmer visits
Visitors see whether to come now or later — on your website before they leave home, or on a screen at the door.
Rooms with their own limit
A meeting room, gym or event space gets its own capacity and its own alert, not just the building as a whole.
Space and energy that follow people
Occupancy by floor, room and hour shows which spaces are underused and when heating, cooling and lighting can ease off.
Events and peak days
Hold entries or open more doors before the room is full, instead of after.
The options
Five ways to keep count, compared
Every method counts people; they differ in who does the counting, whether exits are counted too, and whether anyone besides the person at the door can see the number.
| Method | How it works | Live number | Reliability | Staff at the door |
|---|---|---|---|---|
| Pen and paper | A tally mark for every person in, and out | No | Lowest: easy to miss, hard to share | One per entrance, all day |
| Clicker | +1 per person; most cannot count exits | At that door only | Low: exits and other doors are guesses | One per entrance |
| Carts or tokens | A fixed number handed out at the door | Indirect | Fair, but slows the entrance; not everyone wants one | To hand out and collect |
| Counting app | + and − buttons on a phone, with a capacity setting | On that phone | Depends on the person counting | One per entrance |
| Automatic counters + T.M.A.S. | A sensor over each entrance counts in and out | Everywhere: phone, dashboard, screens, website | Up to 99%+ on adults with the 3D SCOPE II LC | None for counting |
Counting by hand works for a single door on a quiet day. Our free Occupancy Tracker app (iOS, Android) turns a phone into a counter with + and − buttons and a maximum capacity setting, so the person at the door sees the occupancy as a percentage. Beyond one door, or for a full day, the cost is the person: whoever is counting is not serving anyone.
Staff counting at the door aren’t serving customers
Moved off the door, the same people shorten lines, keep the flow moving, help visitors find what they came for — and in a store, turn more visitors into buyers.
And a number on one phone helps no one else
Managers, security, cleaning crews and the visitors themselves all need the live count. Only an automated system puts it everywhere at once.
Automated occupancy monitoring
How it works
1. Count both directions at every entrance
A counter over each entrance counts people coming in and going out, separately, around the clock.
2. Add up the building
T.M.A.S. combines every entrance: occupancy = entries − exits since opening, updated in real time. Wide entrances simply get more than one sensor.
3. Set a capacity, get alerts
Give each location or area its limit. Designated staff — managers, security, the front desk — are alerted when occupancy approaches or passes it.
4. Show the number where it helps
Screenlet, included with the Real-Time plan, is a web page you open on a TV, a tablet or a digital sign at the door. It refreshes live, shows the occupancy of one room or several, and switches between Come in and Stop at your maximum. To build your own display or put the number on your website, the Web API gives you the live count.
5. Keep the record
Occupancy by hour, day and location, exported in seconds for compliance reports, planning and staffing.
What we recommend
A 3D counter, because occupancy never forgets a miss
Occupancy subtracts exits from entries all day, so every missed person, in either direction, stays in the number until the next reset. A counter that sees people from above, in both directions at once, keeps the live count close to reality from opening to close.
3D SCOPE II LC + T.M.A.S. Real-TimeLive occupancy
$1,149.95 per sensorReal-Time plan $51.95 a monthOne PoE cable
Mounted on the ceiling over the entrance, it counts people walking side by side and in groups, in and out at the same time, and can leave out carts and children. Rated up to 99%+ on adults, with a written 95% minimum for two years; our team calibrates it remotely. The Real-Time plan adds the live occupancy dashboard for one or many locations, capacity alerts, Screenlet for entrance screens, the Web API to build your own display or integrate the count, and reports. With it, the Storetraffic app shows staff the live count and where it stands against your maximum, and lets them adjust it by hand if a count goes wrong.
See the 3D SCOPE II LC Counting visits rather than occupancy?
If what you need is how many people came through, by hour, day and week, rather than how many are inside right now, a PEARL wireless door counter with the T.M.A.S. Standard plan covers it for less: $499.95 per door and $33.95 a month per device, or $27.95 prepaid yearly. It installs on the door frame in minutes, with no wiring. For a live count you can act on, stay with the 3D SCOPE II LC and the Real-Time plan.
The cost
A sensor costs less than two weeks of counting at the door
| One entrance | First week | First year | Each year after |
|---|---|---|---|
| A person counting, 62 hours a week at $15 an hour | $930 | $48,360 | $48,360 |
| 3D SCOPE II LC + Real-Time plan, prepaid yearly | $1,689.35 | $1,689.35 | $539.40 |
The sensor and a year of the Real-Time plan cost about what 13 days of a person counting at the door do. Prefer to pay monthly? The plan is $51.95 a month. Prices in USD for one sensor; a wide entrance may need two. You may still want someone at the door to welcome people — the counting is what they no longer have to do.
Where it’s used
Live occupancy, location by location
Offices and buildings
Floors, rooms and whole buildings: capacity, space use and who is in on any given day.
Meeting rooms and event spaces
Hold a room at its limit and see which ones are free right now.
Libraries
Visitors in the building right now, peak hours for staffing, and the visit counts your reports require.
Museums
Gallery and building capacity, timed entries and a calmer visit on busy days.
Stores and malls
Live occupancy on peak days, and the same counts give you traffic and conversion every day.
Places of worship and events
Seat the room, open the overflow space in time, and know attendance for every service or event.
FAQ
Occupancy monitoring questions
What is the difference between occupancy monitoring and people counting?
People counting records how many people come in and go out over a period: visits per hour, day or week. Occupancy monitoring uses the same counts to show how many people are inside right now: entries minus exits since opening, updated live. That needs accurate counts in both directions, all day.
How accurate is live occupancy?
As accurate as the counts in both directions, because a missed exit stays in the number until the next reset. With a ceiling-mounted 3D counter such as the 3D SCOPE II LC, rated up to 99%+ on adults with a written 95% minimum for two years, the live number stays close all day, and staff can correct it in the Storetraffic app at any time. More in our guide to people counter accuracy.
Can I show the live occupancy on a screen at the entrance or on our website?
Yes. Screenlet, included with the Real-Time plan, is a URL you display on a TV, a tablet or a digital sign at the entrance. It refreshes live, shows the occupancy of one room or several, and switches between Come in and Stop when you reach your maximum, so visitors know whether to come in or wait without staff at the door. For your website or your own systems, the Web API provides the live count, so your team can build its own display or integrate it.
Can I monitor a single floor or a meeting room?
Yes. Put a counter at each way into the area and give it its own capacity; T.M.A.S. shows each area live and alerts staff as it fills. Washrooms are different: cleaning after a set number of visits only needs a visit count, not live occupancy. More on our page about people counting for buildings.
Is the free Occupancy Tracker app enough?
For one entrance counted by hand, the free Occupancy Tracker app (iOS, Android) has + and − buttons and a maximum capacity setting. For automatic counting, alerts to staff, several entrances or locations, entrance screens and reports, use counters with the T.M.A.S. Real-Time plan. On its own, the free Storetraffic app shows hourly visitor counts, not live occupancy; with the Real-Time plan it shows the live count, where you stand against your maximum, and lets you adjust it by hand if a count goes wrong.
See your live occupancy before you commit
A 20-minute demo shows the live dashboard, alerts and Screenlet on real data. Or start counting by hand today with the free Occupancy Tracker app.
Further reading