A first-cut CCTV plan for a factory comes from four counts and three unit prices: how many machines one camera can watch, how many gates, stores and perimeter points need their own camera, how long you keep footage and at what bitrate. With 40 machines, four machines per camera, 3 gates, 2 stores or dispatch bays and 4 perimeter points, the calculator gives 19 cameras, about 12.3 TB of storage for 30 days, a PoE load of about 124 W and a budget of about ₹2.05 lakh at the illustrative prices.
How the calculator works
The calculator takes twelve inputs:
- Machines on the floor. Every machine whose running or standing you want to see.
- Machines one camera can cover. How many machines one camera sees clearly enough to tell running from idle. Four is a starting assumption for a row of mid-size machines; on a crowded floor or with tall machines it can be two.
- Gates and entries. One camera per gate, door or loading entry.
- Stores, dispatch and loading areas. One camera per area.
- Perimeter and yard cameras. Fence lines, yard, scrap area, parking.
- Days of recording to keep. Your retention window.
- Bitrate per camera (Mbps). The average data rate the recorder stores for one camera.
- Recording hours a day. 24 for continuous recording; fewer if you record only working hours.
- PoE power per camera (W). The power each camera draws from the switch over the network cable.
- Price per camera (₹), NVR, cabling and install per camera (₹) and storage cost per TB (₹). Your own quotes. The defaults are illustrative assumptions, not market prices, and Mama names no prices.
The formulas:
Cameras = ceil(machines ÷ machines per camera) + gates + stores and dispatch + perimeter
Storage (TB) = cameras × bitrate (Mbps) × 3,600 × hours a day × days ÷ 8 ÷ 1,000,000
PoE load (W) = cameras × watts per camera
Budget (₹) = cameras × (camera price + NVR, cabling and install) + TB × ₹ per TB
The machine count is rounded up, so 41 machines at four per camera needs 11 machine cameras, not 10.25. If you set machines per camera to zero, the machine term drops out. Storage uses decimal terabytes (1 TB = 1,000,000 MB), the way disks are sold. Mbps × seconds gives megabits, ÷ 8 gives megabytes.
Worked example (India)
A mid-size engineering unit with 40 machines on one floor. All figures are assumptions for illustration; they are the calculator's default inputs.
| Input | Value | Basis |
|---|---|---|
| Machines | 40 | assumption |
| Machines per camera | 4 | assumption |
| Gates and entries | 3 | assumption |
| Stores, dispatch, loading | 2 | assumption |
| Perimeter and yard | 4 | assumption |
| Retention | 30 days | assumption, not a legal minimum |
| Bitrate | 2 Mbps | assumption; read yours off the recorder |
| Recording hours | 24 h/day | continuous |
| PoE per camera | 6.5 W | assumption; check the datasheet |
| Camera price | ₹6,000 | assumption |
| NVR, cabling, install | ₹2,500/camera | assumption |
| Storage | ₹3,500/TB | assumption |
| Cameras | 19 | ceil(40 ÷ 4) = 10, + 3 + 2 + 4 |
| Storage | 12.3 TB | 19 × 2 × 3,600 × 24 × 30 ÷ 8 ÷ 1,000,000 = 12.31 |
| PoE load | 124 W | 19 × 6.5 = 123.5 W, rounded |
| Budget | ₹2.05 lakh | 19 × ₹8,500 = ₹1,61,500, + 12.31 TB × ₹3,500 = ₹43,092; total ₹2,04,592 |
Two things stand out. Machines take just over half the cameras (10 of 19); the other nine go to gates, stores and the perimeter. And storage is about a fifth of the budget at these prices. Doubling retention to 60 days adds another 12.3 TB, not another set of cameras.
What typical numbers look like
- Storage per camera is fixed arithmetic. 1 Mbps recorded for 24 hours is 1 × 86,400 ÷ 8 = 10,800 MB, or 10.8 GB a day. At the default 2 Mbps, one camera fills about 21.6 GB a day and 648 GB in 30 days. Read the actual bitrate of one of your own cameras off the recorder and multiply; that beats any table. Our CCTV storage guide has GB-per-day bands by resolution and codec.
- Standard PoE gives each port 15.4 W at the switch. An IEEE 802.3af port must supply at least 15.4 W, and after losses in a worst-case 100 m cable the camera is guaranteed 12.95 W (IEEE 802.3af task force, "Working the numbers"). A fixed camera drawing 6.5 W fits comfortably; PTZ cameras and heaters may not. The PoE budget guide covers PoE+ and headroom.
- Cameras per machine. We found no credible published benchmark for how many machines one camera should cover on an Indian floor. It depends on machine height, aisle layout, lens and light. The lens and DORI calculator shows how many pixels per metre a lens gives at a distance.
- Retention. There is no single number that applies to every factory. See how long a factory must keep CCTV footage before you settle on 30 days.
What this number does not tell you
- Where the cameras go. A count is not a plan. A tall machine, a mezzanine or a column can hide half a row from a camera that looks fine on a drawing. Placement is decided by walking the floor; see where to place cameras on a shop floor.
- Whether one camera can really watch four machines. That depends on distance and lens. To see whether a machine is running or idle you need enough pixels on the machine, not on faces. The DORI explainer gives the pixel-density levels.
- Real disk to buy. The TB figure is raw footage. Busy scenes, motion at night under IR, RAID parity and the gap between decimal TB and what the operating system shows all push the disk you buy higher.
- Everything outside the per-camera prices. UPS and generator backup for the switch and recorder, surge protection on yard runs, network switches, racks, poles and civil work are not in the budget unless you fold them into the install figure. GST is not added.
- Power during a cut. The PoE figure is the load on the switch, not runtime. If the switch has no UPS, every camera goes dark in a power cut.
- Analytics. The budget is for recording. Software that reads the video to tell you which machine stood idle is a separate cost.
Related guides
- How Many Cameras Does a Factory Floor Actually Need?
- CCTV Storage Calculator: How Many TB for N Cameras x 45 Days (India)
- PoE Power Budget for Factory Cameras in India: Sizing It Right
- DORI (IEC 62676-4) Explained: Pixels per Metre, Datasheet Distances and What a Factory Needs
- CCTV lens and DORI calculator
FAQ
How many CCTV cameras does a factory need? Count the machines one camera can watch clearly, then add one camera per gate, store or dispatch bay and perimeter point. With 40 machines at four per camera, 3 gates, 2 stores and 4 perimeter points, that is 19 cameras. Treat it as a first cut and confirm by walking the floor.
How much storage do 19 cameras need for 30 days? At 2 Mbps each and 24-hour recording, about 12.3 TB of raw footage. The formula is cameras × Mbps × 3,600 × hours × days ÷ 8 ÷ 1,000,000. Buy more than the raw figure.
How do I calculate the PoE budget for factory cameras? Multiply the number of cameras by the power each one draws. Nineteen cameras at 6.5 W is about 124 W. Choose a switch whose total PoE budget is comfortably above that, and check each camera's datasheet for its worst-case draw with IR on.
What does a factory CCTV system cost in India? It depends on your quotes. The calculator multiplies cameras by camera price plus per-camera NVR, cabling and installation, then adds storage. At the illustrative defaults, 19 cameras come to about ₹2.05 lakh before GST, UPS and civil work.
Should I record 24 hours a day? If you want footage of nights, holidays and the perimeter, yes. Recording only working hours cuts storage in proportion: 12 hours a day halves the TB figure.
Mama can draw a camera plan for your own floor, with each camera placed against your machines, gates and stores. Leave an email or phone in the form below.