Plant Grow Light Calculator – Find the Best Lighting Hours and Distance for Your Plant
Tips:In the instruction manual of your lamp, you could find the description of the light intensity, for example, 200μmol/s/m² @ 1FT. 1FT represents the reference distance of 1 feet. (1 foot is approximately equal to 30 centimeters.)

Best Lighting Distance and Hours

Tips:If recommended hours is larger than 24 in the results, it means the lighting intensity of your grow lamp is too weak. Even if using the lighting for the whole day 24 hours is not enough.
  • Plant:
  • PPFD of Your Growing Lights (μmol/s/m²):
  • Reference Distance of PPFD (cm):

  • Recommended Min Lighting Distance (m):
  • Recommended Max Lighting Distance (m):
  • Recommended Min Lighting Time (hour):
  • Recommended Max Lighting Distance (hour):
Plant Grow Light Calculator – Find the Best Lighting Hours and Distance for Your Plant

Plant Grow Light Calculator – Find the Best Lighting Hours and Distance for Your Plant

Use this plant light calculator to find the optimal lighting distance and daily light duration for your indoor plants. By entering your plant name, the intensity of your grow light (measured in μmol/m²/s), and the distance at which this intensity was measured. Our tool calculates the recommended setup based on scientific values such as DLI (Daily Light Integral) and PPFD (Photosynthetic Photon Flux Density).


Different plants require different levels of light to grow well. Some houseplants like peace lilies prefer low light. Some others like lavender or tomatoes need full sun. This tool helps you understand whether your current grow light setup is sufficient for healthy plant growth. It calculates the best distance between your grow light and the plant. It also calculates how many hours you should keep the light on each day.


Whether you’re using LED grow lights or traditional fluorescent lamps, this calculator takes the guesswork out of plant lighting. No need to estimate the light manually any more! Simply enter the light intensity and distance, and let the system tell you what is best for your plant’s needs.


For best results, make sure your grow light’s specifications are accurate. You also need to know the type of plant you’re growing. Our database includes recommended light levels for a wide range of common garden and houseplants, helping you achieve healthier, faster-growing plants.