Convert lux readings to PPFD (µmol/m²/s) for grow light planning, or convert PPFD to lux. The conversion factor depends on the light source spectrum — select yours below for the most accurate result.
Important: A lux meter measures human-perceived brightness weighted toward green/yellow light (555nm peak). PPFD measures all photosynthetically active wavelengths (400-700nm) equally. This conversion is an estimate — a dedicated PAR meter gives exact PPFD readings. Accuracy varies by +/- 15% depending on actual spectrum.
Conversion direction
For DLI calculation
Light source — affects conversion factor
Sunlight
0.0185 factor
Full spec LED
0.0160 factor
Quantum board
0.0150 factor
HPS
0.0120 factor
Metal halide
0.0145 factor
CMH / LEC
0.0150 factor
T5 fluorescent
0.0135 factor
Blue-heavy LED
0.0175 factor
Warm white LED
0.0140 factor
Please enter a value to convert.
PPFD result
0 umol/m2/s
0
PPFD (umol/m2/s)
0
Lux
0
DLI (mol/m2/day)
DLI context — what crops can this support?
Same lux reading across different light sources
Light sourceFactorPPFDDLI
Input value
Light source selected
Conversion factor
PPFD result
DLI at 18h photoperiod
Formula
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