Photosynthesis Rate and Light Response Calculator
Calculate net photosynthesis rate at a given light intensity using the rectangular hyperbola model.
Find light compensation and saturation points for plant biology.
Photosynthesis Rate Results
Rectangular Hyperbola Model Net photosynthesis as a function of light intensity:
A_net = (Amax × I / (I + Ik)) - Rd
Where:
- A_net = net CO2 assimilation rate (µmol CO2/m²/s)
- Amax = maximum gross photosynthetic rate (light-saturated)
- I = light intensity (µmol photons/m²/s PAR)
- Ik = light saturation point estimate (µmol/m²/s)
- Rd = dark respiration rate (CO2 released in darkness)
Light Compensation Point (LCP) The light intensity at which photosynthesis exactly balances respiration — net A = 0. Below this point the plant loses carbon.
Light Saturation Point The light intensity at which further increases in light give no more photosynthesis.
Typical Plant Ranges
- Sun plants (wheat, corn, tomato): saturate at 1,000–1,500 µmol/m²/s
- Shade plants (ferns, mosses): saturate at 200–400 µmol/m²/s
- Full sunlight outdoors: ~2,000 µmol/m²/s PAR
- Indoor grow lights: 200–800 µmol/m²/s PAR
PAR Photosynthetically Active Radiation — the 400–700 nm wavelength band that plants use for photosynthesis.