Grow Light PPFD
Size a grow light from target PPFD and area.
About Grow Light PPFD
Target intensity times canopy area yields total photon output, divided by fixture efficacy for wattage. PPFD and DLI are the scientific yardsticks for indoor growing, where guessing leaves crops leggy or scorched.
Formula
Grow Light PPFD
PPF = PPFD x area(m2); watts = PPF / efficacy; DLI = PPFD x hours x 0.0036
- PPF
- Total photons the fixture emits per second
Worked example
With the default values below, Grow Light PPFD returns PPF Required of 111.5. Change any input above and every figure here is recalculated in your browser.
Inputs used
- Target PPFDminimum 0 umol/m2/s
- 300 umol/m2/s
- Canopy areaminimum 0.1 sq ft
- 4 sq ft
- Light hoursminimum 1 h
- 16 h
- Fixture efficacyminimum 0.1 umol/J
- 2.3 umol/J
Results
- PPF Required
- 111.5 umol/s
- Recommended Power
- 48 W
- Daily Light Integral
- 17.3 mol/m2/day
Step by step
- 1Values used
- 2Grow Light PPFD
- 3PPF Required= 111.5 umol/s
- 4Recommended Power= 48 W
- 5Daily Light Integral= 17.3 mol/m2/day
Assumptions and limits
- The result is derived only from the 4 inputs listed above. Anything not among them is not part of the calculation.
- In particular, this calculator does not take inflation, tax or fees or charges into account.
- Figures are rounded for display to 1 decimal place, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.
How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.
Frequently Asked Questions
How is Grow Light PPFD calculated?
PPF = PPFD x area(m2); watts = PPF / efficacy; DLI = PPFD x hours x 0.0036 Target intensity times canopy area yields total photon output, divided by fixture efficacy for wattage.
Why does Grow Light PPFD matter?
PPFD and DLI are the scientific yardsticks for indoor growing, where guessing leaves crops leggy or scorched.
What values do I need to enter?
This calculator takes 4 inputs: Target PPFD, Canopy area, Light hours, Fixture efficacy. The pre-filled defaults are a realistic starting point — replace them with figures from your own environment for a result you can act on.