Seasons and Greenhouses
Vapor Pressure Deficit Calculator
Calculate VPD from saturation and actual vapor pressure. The form keeps the source measurements beside the calculated vapor pressure deficit.
Enter values for vapor pressure deficit
Read each Vapor Pressure Deficit field note before calculating vapor pressure deficit.
Input definitions for vapor pressure deficit
The Vapor Pressure Deficit input panel defines Saturation vapor pressure and Actual vapor pressure. Note any Vapor Pressure Deficit conversion.
- Saturation vapor pressure
- Default in Vapor Pressure Deficit: 2.34 kPa.
- Actual vapor pressure
- Vapor Pressure Deficit currently demonstrates 1.52 kPa; substitute the observation being evaluated.
Applying the vapor pressure deficit result
Recalculate after changing a covering, setpoint, ventilation rate, crop load, or equipment capacity. Use the Transplant Harvest Day tool when estimated harvest day needs its own calculation.
Formula for vapor pressure deficit
Vapor Pressure Deficit finds the difference using Saturation vapor pressure and Actual vapor pressure.
Vapor Pressure Deficit evaluates saturation vapor pressure at 2.34 kPa and actual vapor pressure at 1.52 kPa as 0.82 kPa.
Reading vapor pressure deficit
Vapor Pressure Deficit summarizes its formula as Vapor pressure deficit. Target planting day is available from Planting Date Offset Calculator.
Vapor Pressure Deficit in practical terms
Vapor Pressure Deficit focuses on Vapor pressure deficit and combines Saturation vapor pressure and Actual vapor pressure.
Use vapor pressure deficit to calculate VPD from saturation and actual vapor pressure, then inspect saturation vapor pressure in the field.
Vapor pressure deficit: condition to verify
Leaf temperature can differ from greenhouse air temperature.
Documenting vapor pressure deficit
Archive the Vapor Pressure Deficit inputs—Saturation vapor pressure and Actual vapor pressure—beside Vapor pressure deficit.
A short source note for saturation vapor pressure is enough to distinguish evidence from an assumption.
When the garden work is finished, append the actual vapor pressure deficit rather than revising the prediction. Estimated covered temperature also belongs in Row Cover Temperature Gain Calculator.
A second Vapor Pressure Deficit scenario
In a Vapor Pressure Deficit sensitivity check, compare saturation vapor pressure at 2.34 kPa and 2.574 kPa. Vapor pressure deficit evaluates to 0.82 kPa and 1.05 kPa, respectively.
Both cases hold actual vapor pressure unchanged; preserve the other Vapor Pressure Deficit inputs too.
Prefer measured saturation vapor pressure ranges in Vapor Pressure Deficit.
Clarifying the Vapor Pressure Deficit result
How does “Leaf temperature can differ from greenhouse air temperature.” affect vapor pressure deficit?
Vapor Pressure Deficit uses the entered numbers only. Let saturation vapor pressure reflect that condition before calculating.
Can Vapor Pressure Deficit guarantee field or greenhouse conditions?
No. The vapor pressure deficit value reflects the entered dates or readings. Confirm it with a current forecast or sensors positioned near the crop.