MLS Maker Label Studio
Cited category: Agriculture & Forestry

Cannabis DLI (Daily Light Integral) Calculator

Calculate grow-light DLI from PPFD and photoperiod, then compare it with seedling, vegetative, or flowering target bands.

Inputs

Use measured canopy PPFD and the daily light schedule for one crop stage.

Formula: DLI (mol/m2/day) = PPFD (umol/m2/s) x photoperiod (hours) x 0.0036. Stage target bands: seedling 12-20, vegetative 25-40, flower 40-60 mol/m2/day.

umol/m2/s at canopy level

hours of light per day, 0-24

target band in mol/m2/day

used to solve required PPFD or hours

Results

Updates automatically when inputs change.

Current DLI

Not calculated

mol/m2/day from PPFD x hours x 0.0036

Required PPFD

Not calculated

to reach target DLI at current photoperiod

Required Hours

Not calculated

to reach target DLI at current PPFD

Waiting for valid inputs

Enter PPFD and photoperiod to compare against the selected crop-stage band.

PPFD

Not entered

Photoperiod

Not entered

Crop Stage

Not selected

Target DLI

Not entered

Self-tests have not been run.

About the Cannabis DLI (Daily Light Integral) Calculator

Licensed cultivators, controlled-environment growers, and lighting consultants use a cannabis DLI calculator to convert PPFD and photoperiod into daily light integral. Enter canopy light intensity and hours of light to estimate moles of photosynthetically active photons per square meter per day. It helps compare lighting recipes across propagation, vegetative, and flowering stages while staying within plant and facility constraints.

How it works

  1. Measure or estimate average canopy PPFD across the grow area.
  2. Enter the photoperiod in hours per day.
  3. Calculate DLI using PPFD times hours times 0.0036.
  4. Compare the result with cultivar, stage, CO2, temperature, and nutrition targets.
  5. Confirm cultivation activity complies with applicable licensing laws.

Frequently asked questions

How is cannabis DLI calculated?

DLI equals average PPFD multiplied by photoperiod hours multiplied by 0.0036. The result is expressed as moles of photosynthetically active photons per square meter per day.

Is higher DLI always better for cannabis?

No. Plant response depends on genetics, growth stage, CO2, temperature, humidity, root health, nutrition, and stress tolerance. Excess light can reduce quality or waste energy if other conditions are limiting.

Should I use center PPFD or average PPFD?

Use an average across the canopy when planning DLI. A single center reading can hide low-light corners or hot spots that affect uniformity and crop response.

How does photoperiod affect DLI?

DLI increases when the same PPFD runs for more hours. In photoperiod-sensitive crops, lighting duration also affects plant development, so do not change hours only to hit a DLI target.

Does this calculator address cannabis compliance?

No. It only calculates light exposure. Cultivation legality, licensing, energy reporting, pesticide rules, and production controls vary by jurisdiction and must be checked separately.

References