GPT-5.6 Luna: cost, energy and CO₂ per token
What is the footprint of GPT-5.6 Luna? GPT-5.6 Luna emits about 62 g of CO₂e, uses 729 mL of water and 141 Wh of electricity per million generated tokens. Per million input tokens: 11 g of CO₂e, 124 mL of water, 24 Wh. Public price: €1 per million generated tokens, €0.17 for input.
Factors tokenclimate-v6-2026-09, updated on , low confidence. Sources and equations in the methodology.
Key figures, per million tokens
| Energy | CO₂e | Water | Price | |
|---|---|---|---|---|
| Input tokens | 24 Wh | 11 g | 124 mL | €0.17 |
| Generated tokens | 141 Wh | 62 g | 729 mL | €1 |
Of the 26 models in the TokenClimate registry, GPT-5.6 Luna ranks 6th for carbon intensity per million generated tokens, below the median (681 g). The gap with GPT-6 Luna, the registry's most frugal, is still ×2.7.
Frequently asked questions
How much CO₂e for 1 million tokens with GPT-5.6 Luna?
About 62 g per million generated tokens and 11 g per million input tokens (factors tokenclimate-v6-2026-09 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?
Low confidence: extrapolated from another model, or estimated by a parametric tool.
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.
Infrastructure parameters
Datacenter parameters applied to this provider (the equations live in the methodology). (Jegham et al., arXiv:2505.09598 (v6))
| PUE | 1.12 |
| Grid carbon intensity (CIF) | 0.35 kgCO₂e/kWh |
| On-site water (WUE) | 0.3 L/kWh |
| Off-site water (EWIF) | 4.35 L/kWh |
| Amortised manufacturing (embodied) | 49 gCO₂e/kWh |
Price
Public provider prices. (developers.openai.com, pricing)
Full equations and assumptions in the methodology.