Calculator
Lighting and Luminaire Count Calculator
Change the inputs to match your equipment. Results update automatically.
Formula
N = ceil(E × L × W / (Φ × UF × MF))E_ortalama = N × Φ × UF × MF / (L × W)P = N × luminaire watts; energy = P / 1000 × hours/day × days Worked example
For 10 × 6 m, 500 lx, 4000 lm per luminaire, UF 0.60 and MF 0.80: N = 30000 / 1920 = 15.625, rounded up to 16. Estimated illuminance is 512 lx. At 36 W each, the load is 576 W; 8 hours/day for 22 days uses 101.376 kWh.
Lux and lumens measure different things
Lumens describe luminous flux leaving the luminaire; lux describes light reaching a unit area of the work plane. The utilization factor accounts for the fraction reaching that plane. The maintenance factor accounts for deterioration over time. Use luminaire output, not the bare LED-chip rating.
Choose factors for the actual room
Utilization depends on photometric distribution, room geometry and surface reflectances. Maintenance depends on depreciation and the cleaning plan. The example values 0.60 and 0.80 are not universal. Determine inputs from the luminaire data and your maintenance assumptions.
A count is not a layout
The fractional count is rounded up and average illuminance is recalculated. The same count placed differently can leave dark areas or cause glare. Daylight, emergency lighting, uniformity and regulatory compliance are outside this arithmetic model.