Grow Light Calculator

Grow light calculators match light intensity (PPFD) and power to the plant\. Use this calculator for accurate, instant results.

The calculator uses the standard published formula for grow light. Results are accurate to the precision of the inputs you provide. For financial, medical, or legal decisions, always verify with a qualified professional.

This calculator works with inches, square metres, square feet, watts. You can enter values in the units shown — the calculator handles all conversions internally.

The core formula is: DLI = PPFD × photoperiod hours / 10,000. Each step in the calculation is shown so you can verify the result manually.