How to Calculate Grow Light
What is Grow Light?
Grow light calculators match light intensity (PPFD) and power to the plant's growth stage. LED grow lights are the most efficient choice at 80–120+ lumens per watt.
Formula
Step-by-Step Guide
- 1PPFD (μmol/m²/s): seedlings 100–300; veg 400–600; flower 600–900
- 2Wattage guide: ~20–50W per sq ft depending on growth stage
- 3DLI = PPFD × photoperiod hours / 10,000
- 4Higher DLI = faster growth (to a point)
Worked Examples
Frequently Asked Questions
What is Grow Light?
Grow light calculators match light intensity (PPFD) and power to the plant\. Use this calculator for accurate, instant results.
How accurate is the Grow Light calculator?
The calculator uses the standard published formula for grow light. Results are accurate to the precision of the inputs you provide. For financial, medical, or legal decisions, always verify with a qualified professional.
What units does the Grow Light calculator use?
This calculator works with inches, square metres, square feet, watts. You can enter values in the units shown — the calculator handles all conversions internally.
What formula does the Grow Light calculator use?
The core formula is: DLI = PPFD × photoperiod hours / 10,000. Each step in the calculation is shown so you can verify the result manually.
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