☀️ Daily Light Integral Calculator
Enter your grow light’s PPFD (light intensity) and daily photoperiod to calculate the Daily Light Integral your plants are receiving.
What this calculator does
The Daily Light Integral Calculator converts a grow light’s instantaneous intensity (PPFD) and how many hours it runs each day into DLI — the total amount of usable light a plant’s canopy receives over a full day.
How the formula works
DLI is calculated as DLI = (PPFD × photoperiod in seconds) ÷ 1,000,000, converting micromoles of light per square meter per second into total moles of light per square meter per day. This single number lets growers compare lighting setups with different intensities and schedules on equal footing.
- Leafy greens and herbs generally do well around 12-17 mol/m²/day
- Fruiting crops like tomatoes and flowering cannabis often target 25-40+ mol/m²/day
A note on accuracy
Actual plant response also depends on light spectrum, CO2 levels, temperature, and crop-specific tolerances, so use DLI targets as a general growing guideline rather than an exact requirement for every species.