Smoke Detector Placement Planner
On a smooth flat ceiling each smoke detector protects a square whose side is the maximum spacing. Enter the room size, the maximum detector spacing and the ceiling height to get a suggested detector count, the grid layout, and the actual even spacing along each wall. An indicative planning estimate — it runs entirely in your browser and stores nothing.
- • Keep every detector ≥ 0.5 m from walls, light fittings and away from AC supply vents.
- • The first detector in a row sits within about half the spacing of a wall.
- • On a pitched roof mount within ~0.9 m of the apex — not in the dead-air at the very peak or in the corners.
- • A beam deeper than ~10% of the ceiling height acts like a wall — treat each bay as its own area.
This is an indicative planning estimate, not a compliant fire design or a statutory calculation. The actual number, spacing and detector type depend on your occupancy classification, building height, ceiling geometry and the requirements of the local Authority Having Jurisdiction. A licensed fire consultant must design the detection system to NBC Part 4 / IS 2189, and the local fire officer / AHJ signs it off. A wrong number here can cost lives — verify everything before you buy or install.
Related Guides — Deep-dive reading
Heat Detectors in India (2026): Fixed-Temperature vs Rate-of-Rise and Where to Use Them
The detector for places where smoke alarms cry wolf - kitchens, garages, boiler and DG rooms, dusty or steamy stores. How heat sensing works, the two trigger types, and why it is a backup, never a bedroom substitute.
SecurityGas Detectors in India (2026): Combustible-Gas Sensing, LPG vs PNG & the Mounting-Height Rule
How combustible-gas detectors sense a leak before it can explode, why gas density decides whether you mount the unit LOW for LPG or HIGH for PNG, and how to place, test and maintain one.
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Six layouts, spacing rules, the floor-plan method, mixing media and room-by-room — for Indian homes
Design StylesRelated Tools — You may also find these useful
Heat Detector Placement Planner
Space heat detectors on a ceiling grid — spaced closer than smoke — for kitchens, garages and dusty plant rooms where smoke detectors nuisance-alarm. Rows, columns and even spacing. An indicative estimate; heat detectors react later than smoke, never use them on escape routes.
Heat GridSmoke Detector Quantity Calculator
How many smoke detectors does a floor need? Enter the area, the coverage per detector and the enclosed rooms and stair landings to get the total — the greater of the area count and the per-space minimum. An indicative planning estimate; a fire consultant designs to NBC.
Detector CountFire Alarm Zone Calculator
Split a building into fire-alarm detection zones so the panel shows where the fire is. Enter floors, area, the per-zone limit and stairwells to size the zones and the panel or addressable loop. An indicative planning estimate; a fire consultant designs to NBC and IS 2189.
Alarm Zones