Plant Light Daily Integral Calculator
Calculate daily light integral from nonoverlapping average-PPFD time blocks and an entered supplemental-light scenario.
YOUR CALCULATION
Result
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Calculation steps
Work through one step at a time or reveal the complete calculation. The steps use your current inputs.
How to calculate
Multiply each block’s average photon flux density by hours and the unit conversion factor, then sum and compare with an entered DLI target.
DLI mol/m²/day=sum(PPFD µmol/m²/s×hours×0.0036)
Worked example
200 µmol/m²/s for 8 h contributes 5.76 mol/m², and 100 for 4 h contributes 1.44: total DLI 7.2. An entered 12 target leaves 4.8, requiring 6.6667 h at 200 PPFD.
Assumptions and input details
PPFD is measured or supplied; no conversion from electrical watts, lumens or lux is assumed. Blocks must be nonoverlapping and total at most 24 h. Combine simultaneous sources within a block’s PPFD. Supplemental time is compared only with remaining unoccupied hours, not added to overlapping existing light. Target, spectrum, photoperiod suitability and plant requirements are not chosen. Up to 30 blocks. DLI is modeled from block averages, not measured by the site.
References: Iowa State University: PPFD, hours and the 0.0036 DLI factor
Using this calculator
Can I enter my own problem?
Yes. Replace the example values with your own inputs. The result, calculation steps, tables and applicable diagrams update from those inputs. Blank or invalid values clear the result; example values are never silently substituted for missing inputs.
Are the results exact?
Results use floating-point arithmetic and displayed rounding. Read the formula, assumptions and any stated data precision before interpreting the result.
Is my input uploaded?
The calculation runs in your browser. No account, file upload or external AI service is required. Inputs are not saved between page reloads.
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