CCTV Coverage Calculator.
— Calculator · Coverage · storage · bandwidth · IS 14935 / IEC 62676-4 informed
Surveillance, sized to the building.
Camera density from our planning conventions for each sector, H.265 bitrate per resolution, with IS 14935 / IEC 62676-4 surveillance and NBC Part 4 life-safety practice in view. Tier forces enterprise VMS for healthcare + mall by default.
Camera count
62
56 interior · 6 perimeter
Retention
60 days
Hotel / hospitality default
Recording storage
100.4 TB
RAID-5 on internal bays
Recording bandwidth
155 Mbps
H.265 · continuous record
A planning link that reopens this exact configuration — not a quote.
Built on projects like PM Ekta Mall, Guwahati (Commercial · Retail)
- nvr / vms
- 2 × 32-ch
- head-end
- 32-ch commercial NVR
- storage
- RAID-5 on internal bays
- poe / camera
- IEEE 802.3at / bt class
- camera density
- 7 per 1000 m²
- density basis
- Planning convention — project experience
- codec
- H.265 smart-codec design rate (ITU-T H.265)
- bitrate (4 mp)
- 2.5 Mbps (planning average)
- bitrate (8 mp)
- 4.0 Mbps (planning average)
- bitrate (anpr)
- 3.5 Mbps (planning average)
- poe / camera
- IEEE 802.3at / bt class
- retention
- 60 days — sector / insurance norm
- critical tier
- No
+ Model assumptions (9)− Model assumptions
Indicative planning sizing only — camera count, storage and bandwidth are concept-level figures, not a final design, BOQ or layout. Camera density is a planning convention from project experience (IS 14935 / IEC 62676-4 set image-quality and application practice, not a fixed cameras-per-area figure), retention follows sector / insurance norms, codec is ITU-T H.265 and PoE follows IEEE 802.3 classes. Bitrates here are smart-codec planning averages; a per-model storage estimate lives in the CCTV Storage Retention calculator. A site survey, AHJ review and consultant sign-off refine camera count, mount locations, IR throw, lens FoV and resolution per zone. Pricing follows a written estimate after technical review.
What changes this estimate
- Site walkover — mounts, lens FoV, IR throw per zone
- Privacy zones and consultant / AHJ review
- Per-model bitrate tables (see CCTV Storage Retention)
- Analytics / ANPR lanes and per-zone resolution
A planning link that reopens this exact configuration — not a quote.
Carries the camera counts only — interior as indoor fixed, perimeter as IR / outdoor, at the category planning draw rather than your chosen model’s datasheet figure. PTZ is not inferred; add it on the PoE page.
Method
How this is calculated
Camera count = interior coverage from area ÷ per-camera coverage for the sector, plus the perimeter cameras you specify.
Storage (TB) = cameras × bitrate × 3,600 s × recording hours ÷ 8 ÷ 1,000 per day, × retention days ÷ 1,000 — decimal units (1 TB = 10¹² bytes). The Storage & Retention tool shares this base expression but not these defaults: it adds 20% design headroom and uses per-model datasheet bitrates, so the two match only when that headroom is set to zero and the same bitrate is used.
Worked example — Office · 1,000 m² · 10 perimeter cameras · 8 MP
- Area:
- 1000 m² office
- Perimeter cameras:
- 10
- Recording:
- 24 h/day
- 1 · Total camerasinterior + perimeter = 16
- 2 · Retentionsector default = 30 days
Cameras: 16 · Storage: 20.7 TB over 30 days
Open the calculator and enter the inputs above to reproduce it. Every figure above was computed by the same engine the CCTV Coverage Calculator runs — the example cannot drift from the tool.
Constants and assumptions
- Sector profile: officeper-sector coverage density and default retention encoded in CCTV_SECTORS
- Resolution band bitrate: 4.0 Mbps @ 8 MPconservative smart-codec planning bitrate, 15 fps, medium complexity
ELV · Surveillance · Planning
Camera count, retention storage and recording bandwidth across 8 sector profiles. Densities are planning conventions from project experience, not a code rule.
- Sectors
- 8
- Output
- Indicative
- Density basis
- Planning convention
- Retention
- 30–180 days
· Engineering advisory · CCTV Coverage Calculator
What the camera count predicts about the surveillance estate.
The recommended camera count is the brief-stage budget. The deployment requires the lens-and-mount geometry walkover, the per-camera bitrate measurement and the operator-room handover discipline below.
Deployment observations
- Camera count is the BOQ answer; coverage at the witnessed PPM band is the engineering answer. Identification (250 PPM), recognition (125 PPM) and observation (62 PPM) bands taper with distance — a 50-camera estate may deliver identification across only 18% of the floor plan if the lens-and-mount choice is uniform.
- Per-camera bitrate budgeting against the procurement-stage 2 Mbps default is the leading silent under-spec; H.265 main-profile cameras burst to 6 Mbps in busy lobbies and to 9 Mbps in heavy-motion zones. Storage runs out at 18 days when the spec said 30.
- PTZ cameras carry a 5-7 year service envelope but their preset-recall library is the operational deliverable — patrol presets, alarm presets and operator-recall presets are part of the commissioning hand-over, not an aftermarket configuration exercise.
Redundancy posture
- NVR hot-spare discipline matters more than camera spare count — a failed camera affects one viewpoint, a failed NVR affects 16-64 viewpoints. The AMC inventory holds a named replacement NVR per VMS cluster, not a generic camera-spares pool.
- RAID layout on each NVR (typically RAID-5 or RAID-6) holds through single-disk failure; the AMC inventory holds named replacement disks per NVR class for hot-swap with the existing array preserved.
- VMS service architecture is local-first, supervisor-aggregated — recording continues on each NVR even if the central VMS service is offline. Multi-NVR VMS recovery is a service restart with no data loss.
Environmental considerations
- Outdoor camera enclosures (IP66/67) carry an enclosure-seal refresh on the AMC calendar — every 12-18 months under monsoon exposure, every 24-30 months under dry-climate exposure. Condensation-fog on the lens face is the leading failure mode.
- IR illuminator range bounds night PPM — a 30 m IR-range bullet camera delivers identification PPM at 5-8 m only, recognition at 10-15 m and observation past that. Day PPM and night PPM are separate measurements at commissioning.
- Hilltop and high-wind sites require pole-foundation calculations beyond the catalogue baseline — pole tilt corrupts plate-read accuracy for ANPR and IR coverage for night vision. Foundation depth and rebar profile is specified per pole.
Commissioning discipline
- Per-camera PPM witnessed measurement at commissioning — operator walks a 100-target witness set across day, dusk, night-IR and monsoon profiles for outdoor; the lens and electronic-iris settings are locked against the witnessed profile.
- Patch-panel and PoE port mapping handed over against the architectural floor plan — every camera replacement five years from now is a port-and-cable trace from the architect's drawing, not from a vendor's internal numbering.
- Privacy-zone register (NABH for hospitals, DPDPA for any IT-act-bound facility) is annotated against the camera placement at handover — every camera placement has a written privacy justification that survives an audit.
Lifecycle implications
- PoE camera fleets carry a 6-8 year service envelope under indoor exposure, 5-7 years under outdoor exposure; replacement is like-for-like ONVIF on the existing Cat6 + PoE plant.
- Storage HDDs in the NVR carry a 5-6 year service envelope under continuous capture; the AMC schedule holds a hot-spare disk per NVR class for cold-swap with the existing RAID layout preserved.
- VMS firmware refresh is a configuration baseline export-and-restore exercise; named alarm rules, recording schedules and operator preferences are exported offline before any firmware update and re-loaded after verification.
Expansion readiness
- Camera count expansion (10-20%) typically lives within the existing NVR channel budget and PoE switch port count; beyond that, a new NVR plus a new PoE switch is the minimum incremental scope.
- Analytics-class upgrade (ANPR, face-search, line-cross) from baseline 4 MP is a per-camera and a per-NVR licence exercise on the existing cable plant; AI-class analytics typically require an upgraded NVR class with on-board GPU.
- Multi-site VMS aggregation across geographically separate facilities is supported on most Honeywell and Hikvision VMS classes; the addition is a captive-portal credential exchange and a federation configuration, not a re-cabling exercise.
Verification status: Conditional engineering model — assumptions stated · Adversarially verified and regression-guarded · reviewed 2026-08-30
· Engineering notes
How to read this tool’s output
Stage 2 (survey) or stage 3 (design). Use during early-stage scoping to validate sufficient camera count, retention storage and uplink bandwidth.
The assumptions, limits and reference architectures behind this
What an engineer should know
The assumptions behind the numbers this tool produces.
- Camera count derived from building dimensions, risk profile and target coverage density; default to overlapping coverage at perimeter pinch-points.
- Storage sizing accounts for retention (30/60/90/180 days) × bitrate × camera count. Default bitrate assumes H.265 + smart-codec savings.
When this tool is the right one
The project moments and room types this is built for.
- Retail mall sizing camera count + retention against NBC + sector compliance.
- Industrial warehouse sizing perimeter and yard coverage.
- Educational campus sizing classroom, perimeter and emergency-zone coverage.
What changes the answer in practice
Field conditions that move the result away from the planning figure.
- Perimeter wall height affects camera mount geometry; rooftop-mount adds 6–9 m of cable run per device.
- Lighting condition (always-on lobby vs. variable parking) changes camera selection — IR vs. low-light vs. ColorVu.
Defensible starting architectures
Vendor-neutral reference points, not a recommendation to buy — the right answer is the one that survives your site survey.
- Honeywell or Bosch VMS on dedicated NVR with redundant RAID. Cat6A backbone for all PoE++ camera runs.
Common mistakes
Failure patterns we see on real projects.
- Sizing storage at H.264 bitrates when the proposed cameras are H.265 — over-specifies the recorder.
- Treating retention as flat when sector-specific regulations require 90 or 180 days.
How this lands against adjacent systems
What else has to be agreed before this output is safe to build to.
- Camera count and storage assumptions must be validated against the VMS licence model.
What this tool does not do
Deliberate limits — where the estimate stops and design begins.
- Does not size analytics workloads (face recognition, ANPR) — those add 10–30% CPU and dedicated GPU.
Where this tool fits
The building types this output is calibrated for — and, where we have said so, the ones it is not.
Not the tool to reach for
The standards and technologies this touches
Reference pages for the protocols, standards and systems behind this tool’s output.
· Example use
A 70-bed hospital of around 10,000 m² with ten perimeter cameras lands on roughly 110 cameras at 4 MP, the healthcare sector's 90-day retention and around 255 TB of recording storage on an enterprise VMS tier. The coverage and storage land in a defensible band before any vendor walks in. The same building specced casually goes wrong by 30 cameras either way.
How to use the CCTV coverage
Step 1
Describe the site
Pick the sector profile and enter the covered area in square metres.
Step 2
Add perimeter cameras
Enter the perimeter positions your boundary needs — the tool adds interior coverage from the sector density.
Step 3
Pick resolution and recording hours
Choose the resolution band and daily recording window.
Step 4
Read cameras, storage and retention
The tool returns total cameras, retention days for the sector, and storage in decimal TB.
Step 5
Refine storage per model
Carry the answer into the Storage & Retention tool for codec-aware, per-model sizing.
· Frequently asked
CCTV coverage —
what people ask first.
Why design to NBC and IS codes?
NBC 2016 Part 4 and IEC 62676-4 govern image quality and application practice — how a camera view must perform, not how many cameras a floor needs. The calculator's per-sector camera densities and retention days are planning conventions drawn from project experience and sector and insurance norms, framed so they hold up in that code conversation; the appointed consultant and the authority set the final schedule.
How accurate is the camera count?
It is a brief-stage count, not a final camera schedule. The calculator budgets cameras per 1,000 m² from sector-specific planning densities — it does not model field-of-view or overlap geometry. Stairwells, lift lobbies, exterior corners and privacy zones still need a real walkover before the drawing is issued.
Does it account for low-light and high-contrast scenes?
No — camera-class selection is a walkover decision, not a calculator output. Entrance lobbies, parking ramps and outdoor courtyards typically justify WDR and starlight-class cameras; the calculator budgets counts, storage and recording bandwidth, and leaves the per-location lens and sensor schedule to the design stage.
What about analytics and ANPR?
Both are optional layers. ANPR cameras need dedicated lanes; people-counting and intrusion-analytics need higher resolution and specific mounting. The tool flags the upgrade band; the design conversation defines the count.
Which brands do you specify?
Hikvision and Dahua for value, Axis and Bosch for premium and defence-adjacent, Hanwha and Avigilon for analytics-heavy estates. We are brand-agnostic at concept stage and brand-specific at BoQ stage — chosen on use case, not on margin.
Engineering toolkit
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· Begin
Specifying CCTV
for a real building?
Send the floor plates, the operating context and the retention requirement. We will return a sized design within two working days; pricing follows a written estimate after review.