Terms of Use & Affiliate Disclosure.

Last updated: July 2026

By using vpd-calculator.com (the “Site”) you agree to these terms. If you do not agree, please do not use the Site.

The tool is guidance, not professional advice

VPD Calculator provides vapor pressure deficit figures and target ranges to help indoor growers. The results are educational estimates based on standard formulas (the Magnus equation) and general horticultural guidance. Plants, rooms, and equipment vary. Read your plants and use your own judgment; we are not liable for outcomes from decisions made using the Site.

Accuracy

We work to keep calculations and information correct, but we make no warranty that content is complete, current, or error-free. The Site is provided “as is” and “as available.”

Acceptable use

• You may use the calculator and chart freely for personal and commercial growing.
• Do not scrape, overload, or attempt to disrupt the Site, or misrepresent it as your own product.
• Site design, text, and code are our intellectual property; the VPD concept and formulas are not.

Affiliate disclosure

Some outbound links on this Site are affiliate links. If you click one and buy a product (for example a humidifier, dehumidifier, fan, or environmental controller), we may earn a commission at no extra cost to you. This includes participation in the Amazon Associates program and grow-equipment brand programs.

We only link to gear we consider genuinely useful for hitting VPD targets, and commissions never change the numbers the calculator returns or the guidance we give. Product availability, pricing, and specifications are set by the retailer, not us.

Limitation of liability

To the fullest extent permitted by law, we are not liable for any direct, indirect, incidental, or consequential damages arising from use of the Site, including crop loss, equipment decisions, or reliance on any figure shown.

Third-party links

We are not responsible for the content, policies, or products of sites we link to. Following an outbound link is at your own discretion.

Changes & contact

We may update these terms; the “Last updated” date reflects the latest version. If you have questions, please reach out and we will respond as soon as we can.