STRAIGHT ANSWER
How much water does one ChatGPT prompt use?
There is no single verified number. OpenAI's CEO claimed about 0.32 mL per average query in June 2025, but published no method. The only measured first-party figure is Google's 0.26 mL median for a Gemini Apps text prompt (May 2025), which counts on-site cooling water only.
The context
Published figures range from 0.26 mL (Google, measured, on-site water only) to 10 to 50 mL per response (Li et al., 2023 modeled GPT-3 scenario that also counts water used to generate electricity). They cover different services, dates, and boundaries, so they are not comparable and cannot be used to rank AI models.
The published figures, side by side
Different boundaries, dates, and metrics. This is a reading aid, not a ranking. Do not add the rows.
| Figure | Value | Boundary | Period | Evidence | Source |
|---|---|---|---|---|---|
| Google, median Gemini Apps text prompt | 0.26 mL and 0.24 Wh | On-site cooling water only; excludes electricity-related water | May 2025 point-in-time median | Reported · primary | Google inference study |
| OpenAI CEO, average ChatGPT query | about 0.32 mL and 0.34 Wh | Boundary, sample, and method not published | June 2025 blog post | Reported · primary | Altman, The Gentle Singularity |
| Li et al., GPT-3 scenario | 10 to 50 mL per medium-length response | Direct plus electricity-related water; varies by location and time | 2023 preprint | Modeled | Making AI Less Thirsty |
What this answer does not say
- That every AI prompt uses a bottle of water.
- That ChatGPT uses more or less water than Gemini or Claude.
- That the 0.32 mL claim has been independently measured.