fc to PPF PAR Converter
This calculator converts foot-candles to Photosynthetic Photon Flux (PPF), a measure of Photosynthetically Active Radiation (PAR). The conversion is lamp-specific due to spectral differences between lamps, so make sure to select the PPF value for the type of lamp you took the foot-candle reading from.
Note: Another measure appropriate for plant growth, called YPF PAR or Yield Photon Flux, takes into account not only the photons but also how effectively they are used by the plant. Since red light (or red photons) are used more effectively to induce a photosynthesis reaction, YPF PAR gives more weight to red photons based on the plant sensitivity curve.
Also note: The flowering response for cannabis reacts more positively to red light and as a result its yield is increased when HPS lamps are used (contrary to what PPF ratings may suggest). However, PPF is shown here due to its overwhelming use in rating lamps for conventional (non-cannabis) applications and crops.