Tools
Daily Light Integral Calculator
How much photosynthetically active light a crop receives over a day, expressed as a single number.
What DLI describes
PPFD measures light intensity at a single moment. DLI accumulates that intensity across the hours the crop is lit, giving the total photosynthetically active light delivered in a day. The same instantaneous intensity can produce very different daily totals depending on how long it is sustained.
Where it is used
- Comparing light between seasons, sites or compartments
- Deciding whether supplementary lighting is needed, and for how long
- Checking light levels against a crop’s requirement
How the calculator works
Enter a photoperiod and a PPFD value with a minimum and maximum. The tool returns a grid of DLI values across that range, so the effect of a change in intensity or day length can be read directly.
Contact
Planning a lighting strategy?
Light rarely sits on its own — it connects to climate, crop strategy and system design.