Photosynthesis Rate and Light Response Calculator
Calculate net photosynthesis rate at any light intensity using the rectangular hyperbola model.
Find light compensation and saturation points.
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.