Lux Lumens Calculator

How Lux Lumens works

The calculation uses lux = lumens ÷ area. Lux Lumens uses Lumens reaching surface, Surface area to report Average illuminance.

In the loaded Lux Lumens case, average illuminance equals 200.00 lx. Preserve the baseline before changing a value.

Inputs for Lux Lumens

Lumens reaching surface and Surface area belong to Lux Lumens. Keep source units with lumens reaching surface.

The preset case is instructional rather than prescriptive. Enter the applicable electrical data. For wall-plug efficiency, open Lighting Wall-Plug Efficiency Calculator.

Lumens reaching surface

Example entry: 4000 lm.

Surface area

Example entry: 20 m².

Select the Lumens reaching surface instrument range for Lux Lumens. Record measurement plane, mounting height, beam distribution, reflectance, and maintenance state. Repeat uncertain lumens reaching surface readings before refining average illuminance.

Reading the Lux Lumens result

This output represents Lux Lumens. For daylight factor, use Daylight Factor Calculator.

Finish the selection with standard sizes, operating limits, and transient review.

Keep the Average illuminance definition during conversion. Preserve lx for Lux Lumens. Use average illuminance when interpreting Lighting units.

For Lux Lumens, preserve Lumens reaching surface and average illuminance under the same measurement plane, mounting height, beam distribution, reflectance, and maintenance state record before final use.

Measurement and units

Photometric results depend on fixture distribution, reflectance, mounting, maintenance, and the measured task plane. Check prefixes on lumens reaching surface.

Keep the same electrical reference points across saved cases.

Classify Lumens reaching surface as instantaneous, average, nameplate, or design. Lux Lumens accepts one entry. Separate average illuminance cases when lumens reaching surface varies.

Limits of this calculation

Uniform distribution is assumed.

Lux Lumens omits effects absent from its entered values. Compare this result with Foot-Candles Lux Calculator when illuminance is also needed.

For Lux Lumens, compare Average illuminance with illuminance, uniformity, driver loading, voltage loss, energy use, and maintained output. Document lumens reaching surface tolerance for Lux Lumens. Treat duty separately in Lighting.

A useful Lux Lumens comparison

Record average illuminance before testing a different lumens reaching surface value. For voltage loss, open LED Strip Voltage Loss Calculator.

Document the alternate lumens reaching surface source.

In Lux Lumens, save the Lux Lumens result at 4,000 lm lumens reaching surface, then calculate again at 3,400 lm. The corresponding average illuminance values are 200.00 lx and 170.00 lx. Lux Lumens holds surface area fixed; check Lighting equipment limits.

In Lux Lumens, label Lumens reaching surface by operating state. Keep average illuminance cases separate for measurement plane, mounting height, beam distribution, reflectance, and maintenance state.