Optimize plant growth by calculating the difference between air moisture saturation and actual humidity.
Environment Conditions
60%
Transpiration Drive
0.91kPa
Vegetative
Leaf Sat VP2.81kPa
Air Actual VP1.90kPa
VPD vs Humidity (at 25°C)
About this calculator
Overview
Vapor Pressure Deficit (VPD) is the difference between how much moisture the air *can* hold and how much it *does* hold. It is the primary driver of plant transpiration.
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Pro Tips
Low VPD (< 0.4 kPa): Risk of fungal growth and over-hydration.
Cloning/Early Veg (0.4 - 0.8 kPa): Ideal for root development and young plants.
Vegetative (0.8 - 1.2 kPa): Optimal for healthy foliage growth.
Late Flower (1.2 - 1.6 kPa): Higher stress, helps prevent bud rot in dense flowers.
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Fun Facts
"Think of VPD as the 'thirst' of the atmosphere."
"VPD is independent of temperature, unlike Relative Humidity, making it a better metric."
