Daily Light Integral (DLI) Calculator

Master your grow environment. Enter your light intensity (PPFD) and photoperiod to find the total 'light volume' your plants receive every 24 hours.

Light Intensity (PPFD)*

Light Duration (Hours)*

DLI Calculation (from PPFD): 1. Intensity: Photosynthetic Photon Flux Density (PPFD) in µmol/m²/s. 2. Photoperiod: Total hours of light exposure per day. 3. Conversion: DLI = (PPFD × Hours × 3600) / 1,000,000. Note: 3600 converts hours to seconds, and 1,000,000 converts micromoles (µmol) to moles (mol).

Scenario: Your indoor garden has an average PPFD of 500 µmol/m²/s at the canopy, and your grow lights are on for 18 hours a day. Calculation: 1. PPFD = 500. 2. Hours = 18. 3. DLI = (500 × 18 × 3600) / 1,000,000. 4. DLI = 32,400,000 / 1,000,000 = 32.4 mol/m²/d. Result: Your plants receive a Daily Light Integral of 32.4 mol/m²/d, which is ideal for high-light crops like tomatoes or peppers.

What is Daily Light Integral (DLI)?

Daily Light Integral (DLI) is the total amount of Photosynthetically Active Radiation (PAR) that a plant receives over a 24-hour period. It is measured in moles of light per square meter per day (mol/m²/d).

How is DLI calculated from PPFD?

The formula is: DLI = PPFD × Light Hours × 3600 / 1,000,000. PPFD is measured in µmol/m²/s, so we multiply by 3600 (seconds in an hour) and then by the number of light hours, dividing by 1 million to convert µmol to mol.

Why is DLI important for plants?

DLI is the "total fuel" a plant gets in a day. Different plants have different DLI requirements. For example, microgreens may need 10-12 mol/m²/d, while fruiting crops like tomatoes often require 20-30 mol/m²/d for high yields.