Claude Sonnet: cost, energy and CO₂ per token
What is the footprint of Claude Sonnet? Claude Sonnet emits about 950 g of CO₂e, uses 15.0 L of water and 2.5 kWh of electricity per million generated tokens. Per million input tokens: 45 g of CO₂e, 708 mL of water, 119 Wh. Public price: €9 per million generated tokens, €2 for input.
Factors tokenclimate-v3-2026-09, updated on , high confidence. Sources and equations in the methodology.
Key figures, per million tokens
| Energy | CO₂e | Water | Price | |
|---|---|---|---|---|
| Input tokens | 119 Wh | 45 g | 708 mL | €2 |
| Generated tokens | 2.5 kWh | 950 g | 15.0 L | €9 |
Claude Sonnet emits 39% more than the median of the 26 models in the TokenClimate registry (681 g per million generated tokens), that is ×41 compared with GPT-6 Luna, the most frugal.
One million generated tokens represents about 7 km in a combustion car.
Frequently asked questions
How much CO₂e for 1 million tokens with Claude Sonnet?
About 950 g per million generated tokens and 45 g per million input tokens (factors tokenclimate-v3-2026-09 of the TokenClimate registry).
Where do these figures come from?
Factors published in TokenClimate's versioned registry, each with its citation on this page. The full equations and parameters are in the public methodology, at tokenclimate.com/en/methodology.
What is the confidence level?
High confidence: published estimate specific to this model, fitted on its own points.
How can you measure your organisation's real usage?
The TokenClimate dashboard connects to your organisation's Anthropic, OpenAI or OpenRouter admin keys (stored encrypted) and measures cost and CO₂e per team and per model. You can see it in the demo: tokenclimate.com/demo. Locally, the open source plugin claude-carbon measures a Claude Code session.
Sources and method
Energy per token
The per-token energy factor behind the figures above, published with its citation. (Jegham et al., arXiv:2505.09598 (v6))
Infrastructure parameters
Datacenter parameters applied to this provider (the equations live in the methodology). (AWS Sustainability, millésime 2025)
| PUE | 1.14 |
| Grid carbon intensity (CIF) | 0.287 kgCO₂e/kWh |
| On-site water (WUE) | 0.12 L/kWh |
| Off-site water (EWIF) | 5.11 L/kWh |
| Amortised manufacturing (embodied) | 49 gCO₂e/kWh |
Price
Public provider prices.
Full equations and assumptions in the methodology.