1 glass of milk = 850,000 AI prompts
1 glass of milk equals roughly 850,000 AI prompts on the water side: 255,000 mL, while an average text prompt weighs just 0.3 mL. The math, the source and detailed equivalents are right below, with public, verifiable numbers.
Figures updated on June 30, 2026 · Source : Water Footprint Network : produits animaux (Mekonnen & Hoekstra)
The water of a prompt is what evaporates to cool the data center while it answers. For food and goods we count virtual water: all the water mobilised by production, not just what comes out of the tap. Both compare as orders of magnitude, which is exactly what this page shows.
Why 850,000 prompts?
The math fits in three lines, using public, sourced values:
- 1.1 glass of milk: 255,000 mL (Water Footprint Network : produits animaux (Mekonnen & Hoekstra))
- 2.1 text prompt: 0.3 mL (published range: 0.26 to 0.32 mL)
- 3.255,000 mL ÷ 0.3 mL ≈ 850,000 prompts
In other words, “1 glass of milk” weighs as much as 850,000 questions asked to a generative AI. It is an order of magnitude, not a to-the-decimal measurement: sources publish ranges, and we use a median value, explained in our methodology.
What about a generated image or a reasoning prompt?
Not every AI use weighs the same. A generated image costs about 9 mL and a “reasoning” prompt about 20 mL, versus 0.3 mL for a simple text prompt. So “1 glass of milk” is also roughly 28,333 times one generated image, or 12,750 times one reasoning prompt.
Convert your own usageWhere do these numbers come from?
The value we use for “1 glass of milk” comes from “Water Footprint Network : produits animaux (Mekonnen & Hoekstra)”, referenced like all our data on the Sources page. No number on this page is made up: every value can be traced back to a public document.
On the prompt side, Google and OpenAI report between 0.26 and 0.32 mL of direct cooling water per request; we use 0.3 mL. Counting the upstream water of electricity generation, the figure sits closer to 1.5 mL.