Dr. Greenhouse VPD Calculator

Dr Greenhouse

About this app

With this tool, you can easily calculate the Vapor Pressure Deficit of your grow room’s air.

First, choose your temperature units: Fahrenheit or Celsius. Then plug in the air temperature and relative humidity and click “Calculate.” The resulting VPD (kPa) will be color-coded to indicate whether the grow room climate is humid (blue), vegetative (green), reproductive (yellow), or dry (purple).

The desired VPD depends on the type of plant, its stage of growth, and, in some cases, the time of day. In general, leafy greens, microgreens, and other non-flowering plants enjoy a “vegetative” environment. Flowering and fruiting plants benefit from a “reproductive” environment. Cannabis plants may yield more trichomes and terpenes, if exposed to a “dry” and water-stressed environment in the days leading up to harvest. And a “humid” nighttime environment can improve translocation of nutrients and metabolites to strawberries and other fruiting plants.

Ratings and reviews

A powerful tool that helps to manage my garden. I can perform "what ifs" with temp and humidity to tweak things so my ladies have the perfect environment (VPD). It adds a plain, color-coded message, which specifies whether the calculated VPD is good for "Veg," "Flower," or too wet/dry. It's got the graphic of the VPD chart for reference, too. I think this is a fantastic app and so will you. Thank you to the devs!

Well worth installing really helps you keep your VPD in perfect range.

Doesn't factor in leaf temp. Not true vpd

What’s new

Version 2.0 of the VPD Calculator
includes
the following changes and new features:
Improved user interface
New leaf temperature
based VPD calculator
New RH calculator based on target VPD