Lamps needed
Calculate Lamps needed instantly with the exact formula and a worked example. Free online calculator — no signup.
Lamps needed
Area, m²
Illuminance (lux)
Lumens/lamp
η (util factor)
Lamps needed
12
N
12
More about: Lamps needed
What it calculates
The “Lamps needed” calculator computes Lamps needed from 4 parameters: area, m², illuminance (lux), lumens/lamp, η (util factor).
A standard physics formula used in educational and engineering tasks.
Example calculation
With parameters Area, m² = 20, Illuminance (lux) = 300, Lumens/lamp = 1,500, η (util factor) = 0.5 the result is 12.
How to use
- Enter the parameter values — every field above is adjustable with a slider.
- The result and related metrics are calculated automatically as you type.
- Use the additional metrics shown (if any) where needed.
- Copy the result or bookmark the page.