Climate control tool
VPD Calculator
Calculate vapor pressure deficit from temperature and humidity for hydroponics, indoor growing, grow tents, and greenhouse climate control.
Current room or canopy air temperature.
Choose Celsius or Fahrenheit.
Current relative humidity in the grow space.
Used to compare your result with typical stage targets.
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Air temperature in the grow room.
Choose Celsius or Fahrenheit.
Relative humidity percentage.
Leaf temperature minus air temperature. Negative means leaves are cooler than the air.
Used for stage comparison.
Night conditions often run a lower target than daytime.
Advanced mode is more practical because plant leaves are often slightly cooler or warmer than the surrounding air. Using leaf temperature can give a more realistic VPD value than air temperature alone.
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A useful product for humidity control, airflow, monitoring, or temperature management.
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A useful product for humidity control, airflow, monitoring, or temperature management.
Air temperature in your canopy zone.
Choose Celsius or Fahrenheit.
Difference between leaf temperature and air temperature.
Current relative humidity percentage.
Used for target comparison.
Recommended products for leaf-temperature-driven climate tuning
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A useful product for humidity control, airflow, monitoring, or temperature management.
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A useful product for humidity control, airflow, monitoring, or temperature management.
VPD calculator for hydroponics and indoor growing
This VPD calculator helps growers estimate vapor pressure deficit from temperature and relative humidity so they can manage climate more effectively in hydroponics, indoor growing, greenhouse production, and grow tent environments. It is useful for seedlings, clones, vegetative growth, and flowering plants where climate control directly affects transpiration and plant performance.
The tool includes a simple VPD calculator, an advanced leaf-temperature-based mode, and a leaf temperature helper so growers can tune humidity and temperature with more confidence.
How this VPD calculator works
VPD is the difference between how much moisture the air can hold at a given temperature and how much moisture is actually present. Higher VPD usually means drier air and stronger transpiration demand. Lower VPD usually means more humid air and lower transpiration demand.
In advanced mode, the calculation uses estimated leaf temperature instead of only air temperature, which often gives a more realistic result for practical growing.
What each parameter means
- Air temperature: ambient temperature around the plant canopy.
- Relative humidity: percentage of moisture currently present in the air.
- Leaf temp offset: difference between leaf temperature and air temperature.
- Leaf temperature: actual or estimated temperature of the plant leaf surface.
- VPD: vapor pressure deficit, shown in kPa.
- Plant stage: growth phase used to compare against practical target ranges.
Why VPD matters for growers
VPD affects transpiration, water movement, nutrient transport, stomatal behavior, and plant stress. If VPD is too low, the air may be too humid and transpiration may slow. If VPD is too high, plants may lose moisture too quickly and become stressed.
Managing VPD can help growers make better decisions about humidity, extraction, air movement, temperature, and irrigation strategy.
Typical practical VPD targets
- Clone / seedling: around 0.4–0.8 kPa
- Vegetative stage: around 0.8–1.2 kPa
- Flowering stage: around 1.0–1.5 kPa
These are general-use reference ranges for planning. Final targets depend on crop type, airflow, lighting intensity, CO₂ level, irrigation style, and overall climate strategy.
Best practice for indoor growers
- Use VPD together with temperature, humidity, and irrigation monitoring.
- Check leaf temperature when possible, not only room temperature.
- Do not chase one exact VPD number at all times; work within a practical range.
- Adjust humidity and temperature gradually to avoid plant stress.
- Review VPD together with plant stage, lighting intensity, and airflow conditions.
Shipping. 3 day EU delivery
7 to 15 EUR under 30kg. See more on Shipping details page.
60 days returns
You can get a refund or replacement after up to 30 days from purchase.
But we ussualy stand on customers side, so we can give a 60 days time frame!
2 months post sale expert support
It's free.
We are a team of 10 with a decade of wise expirience in growing and gardening, so if you'll have any need of help, we'll guide you to your goal within 2 months from a purchase.
About us. Our 9 year history
GoToGarden started in 2017 out of personal frustration. Our founder was a hobby grower who spent hours navigating online shops that felt built by people who had never touched a plant — cluttered layouts, vague product descriptions, no real guidance on what to actually buy or why. He knew there had to be a better way.
See more on About us page
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