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Lighting Calculator
This calculator determines the required number of luminaires to achieve standard illuminance levels per EN 12464-1, IS 3646 and SP 52.13330. All calculations are performed client-side — your data never leaves the browser.
How the calculation works
1. The required illuminance (E, lx) is determined for the selected room type per EN 12464-1. 2. Total luminous flux: Φ = E × S / (UF × MF), where UF ≈ 0.5 (utilization factor), MF ≈ 0.8 (maintenance factor). 3. Number of luminaires: N = ⌈Φ / Φ_lamp⌉. 4. Specific power: P_spec = N × P_lamp / S.
Frequently asked questions
How many lumens per m²?
For living rooms 150–300 lm/m², for kitchens and offices 300–400 lm/m². Exact: E = N·F/(S·U·M).
LED or fluorescent?
LED is 5–8× more efficient: 100–150 lm/W vs 60 lm/W. LED is the best choice for homes.
Why does the calculator give 8 fixtures?
N = E·S/(F·U·M), with U = utilization (0.5) and M = maintenance (0.8).