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Security system calculators
Enter your project numbers and get an instant answer. Matching products from our catalog — with price and stock — appear right under the result.
How many TB do I need?
Required storage, number of drives and a matching NVR — by camera count, resolution, codec and retention period.
CalculateIs my switch enough for my cameras?
Sums the maximum power of all devices, adds a 20% reserve and compares it with the switch PoE budget, port count and standard.
CalculateWhat will I see with which mm?
Field of view, frame width and pixels per metre (DORI standard) — from what distance a face, a plate or motion is visible.
CalculateFrequently asked questions
HDD calculatorWhat is bitrate and why does it matter?
Bitrate is the amount of data a camera sends per second (Mbps). Storage depends directly on it: a 4 Mbps camera uses about 43 GB per day. The calculator uses typical bitrates, but you can set your own value for every group.
HDD calculatorHow much do H.265 and H.265+ save?
At the same quality H.265 uses roughly 40–50% less space, and H.265+ (Smart Codec) up to 70% less on static scenes. If your camera and NVR support H.265+, it is the most cost-effective choice.
HDD calculatorWhat does "record on motion only" change?
With motion recording the disk fills only during events. The activity percentage (e.g. 30%) reflects how busy the scene is during the day. For offices, warehouses and night hours it can extend retention 2–3 times.
HDD calculatorWhy is the usable capacity lower than the label?
Manufacturers count TB in decimal units, operating systems in binary units. That is why a 6 TB drive shows as about 5.46 TB in an NVR. The calculator accounts for this ~9% difference automatically.
HDD calculatorWhich drive should I use for CCTV?
For 24/7 recording use surveillance-grade drives (WD Purple, Seagate SkyHawk, Hikvision) — they are built for continuous write workload and vibration. Regular desktop drives fail much sooner.
PoE calculatorWhat is PoE?
Power over Ethernet — the device receives both data and power over a single network cable. No separate adapter or power outlet is needed.
PoE calculatorWhy is a 20% reserve needed?
At night, when IR illuminators, heaters or PTZ motors switch on, devices reach their maximum draw. If the budget has no reserve, cameras reboot or turn off exactly at night.
PoE calculatorWhat is the difference between 802.3af, at and bt?
802.3af (PoE) delivers up to 15.4 W per port, 802.3at (PoE+) 30 W and 802.3bt (PoE++) 60–90 W. Standard IP cameras are fine with af; PTZ and cameras with strong heaters need at or bt.
PoE calculatorWhat if the cable is longer than 100 m?
Ethernet is limited to 100 m. For longer runs use a PoE extender, a switch with "Extend" mode (up to 250 m at 10 Mbps) or fibre with media converters.
Lens calculatorWhat is DORI?
DORI (IEC EN 62676-4) defines 4 levels by pixel density: Detection (25 px/m), Observation (62 px/m), Recognition (125 px/m) and Identification (250 px/m).
Lens calculator2.8 mm or 6 mm?
A short focal length gives a wide angle (2.8 mm ≈ 100°) — good for rooms and yards, but details are smaller. A longer one gives a narrow angle (6 mm ≈ 55°) — to see faces clearly at entrances, gates or checkouts.
Lens calculatorWhy choose a varifocal lens?
With a varifocal lens (e.g. 2.8–12 mm) the field of view can be adjusted after installation. If the distance is not exactly known or may change, it is the safest choice.
Lens calculatorWhat do I need to read licence plates?
Plates need at least 250 px/m (identification) and a proper angle. For moving vehicles dedicated LPR/ANPR cameras with a fast shutter are recommended.