Grownetics VPD Tool — Interactive Chart & Calculator

VPD Heatmap with Growth Stage Zones

-- kPa

Air Temperature

78°F

Relative Humidity

55%

Leaf Temperature Offset

0°F

1.24

kPa

FLOWER ZONE

Leaf VPD (with offset)

1.24

kPa

76-82°F | 45-58% RH | 1.0-1.5 kPa

Higher VPD supports generative development. Keep RH under 60% for mold prevention.

▼ Show Formula Reference

SVP (Saturation Vapor Pressure): SVP = 0.6108 × e^((17.27 × T) / (T + 237.3)) (Tetens equation, T in °C)

VPD: VPD = SVP × (1 - RH/100)

For leaf VPD, substitute leaf surface temperature for air temperature. CropVision measures this directly with IR sensors.