Find the optimal light hours and DLI for every stage of your plant’s life cycle. Enter your PPFD to get exact photoperiod recommendations and electricity costs per grow cycle.
Please select a plant type and enter your PPFD.
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Plants respond to how much light they receive and to how long the light is on, and both change with the stage of growth. Seedlings and young plants in the vegetative stage usually get long days of about 16 to 18 hours, while many flowering crops, including short day plants, are triggered to flower by about 12 hours of light and 12 hours of dark. The calculator turns your PPFD and the hours into a daily light total and an estimate of the electricity cost for the cycle.
Each plant has its own needs. Leafy greens need less light than fruiting crops such as tomatoes and peppers, and too much light can cause stress, while too little gives weak, stretched growth. Long day and short day plants react differently to the length of the dark period, so check what your plant requires.
A uninterrupted dark period matters for plants that are sensitive to it, so avoid light leaks. You can reach the same daily total with a higher intensity for fewer hours or a lower intensity for more hours, and electricity cost depends on the wattage, the hours, and your rate. Measure the PPFD at the canopy, since it falls with distance.