VPD (Vapor Pressure Deficit) Calculator
Calculate the ideal VPD for your cannabis grow room. Optimize temperature and humidity for maximum photosynthesis and transpiration rates.
Frequently Asked Questions
What is the ideal VPD for cannabis?
Clones/seedlings: 0.4-0.8 kPa. Vegetative: 0.8-1.2 kPa. Flowering: 1.0-1.5 kPa. Late flower: 1.2-1.6 kPa. Staying in range optimizes transpiration and nutrient uptake.
What does VPD measure?
VPD measures the difference between the moisture in the air and how much moisture the air could hold at saturation. It determines how fast your plants transpire (release water through leaves), which directly affects nutrient uptake and growth rate.
