Daily Light Integral Calculator
Calculate DLI (mol/m²/day) for optimal plant growth and photosynthesis
Calculate Daily Light Integral
Light Duration
Photosynthetic Photon Flux Density (PPFD)
Photosynthetically active photons per square meter per second
Plant Type (Optional)
Select plant type for specific DLI recommendations
Energy Cost Analysis (Optional)
DLI Results
Daily Light Integral
Light Analysis
Formula used: DLI = PPFD × Light Hours × 3600 ÷ 1,000,000
Calculation: 0 μmol/s·m² × 12.0 hours × 3600 ÷ 1,000,000
Plant type: General plants (optimal: 12 mol/m²/day)
Light Analysis for General plants
Example Calculation
Indoor Lettuce Growing Example
Light duration: 14 hours per day
PPFD: 250 μmol/s·m² (LED grow light)
Plant type: Leafy greens (lettuce)
Recommended DLI: 12-17 mol/m²/day
Calculation Steps
1. Convert time: 14 hours = 14 hours
2. Apply formula: DLI = 250 × 14 × 3600 ÷ 1,000,000
3. Calculate: DLI = 12,600,000 ÷ 1,000,000
4. Result: DLI = 12.6 mol/m²/day
5. Analysis: Perfect for lettuce growth!
DLI Recommendations
Seedlings: 6-8
mol/m²/day
Leafy Greens: 12-17
mol/m²/day
Herbs: 12-17
mol/m²/day
Tomatoes: 20-30
mol/m²/day
Cannabis: 25-40
mol/m²/day
PPFD Guide
0-100 μmol/s·m²
Very low light
100-300 μmol/s·m²
Low light
300-600 μmol/s·m²
Medium light
600-1000 μmol/s·m²
High light
1000+ μmol/s·m²
Very high light
DLI Tips
Measure PPFD at plant canopy level for accuracy
Higher DLI requires more nutrients and CO₂
Adjust photoperiod to optimize DLI levels
Monitor plant response to avoid light stress
Use DLI to compare different lighting setups
Understanding Daily Light Integral (DLI)
What is DLI?
Daily Light Integral (DLI) measures the total amount of photosynthetically active photons that reach a plant surface during a 24-hour period. It's expressed in moles of photons per square meter per day (mol/m²/day).
Why is DLI Important?
- •Determines photosynthesis rate and plant growth
- •Helps optimize artificial lighting systems
- •Improves crop quality and yield
- •Enables precise light management for different crops
DLI Formula Explanation
DLI = PPFD × Light Hours × 3600 ÷ 1,000,000
- DLI: Daily Light Integral (mol/m²/day)
- PPFD: Photosynthetic Photon Flux Density (μmol/s·m²)
- Light Hours: Duration of light exposure per day
- 3600: Conversion factor (seconds to hours)
- 1,000,000: Conversion factor (μmol to mol)
PPFD vs DLI
- PPFD: Instantaneous light intensity at a moment
- DLI: Total light accumulated over 24 hours
- Relationship: DLI = PPFD × Duration
DLI Applications
DLI is essential for greenhouse management, indoor farming, vertical agriculture, and horticultural research. It helps growers optimize energy efficiency, maximize yields, and ensure consistent crop quality regardless of outdoor light conditions.