diff --git a/README.md b/README.md
index a6b2b95..1a7cefe 100644
--- a/README.md
+++ b/README.md
@@ -49,8 +49,9 @@ This is a tool for honest approximation, not precise accounting.
 This project was developed by a human directing
 [Claude](https://claude.ai) (Anthropic's AI assistant) across multiple
 conversations. The methodology was applied to itself: we estimate the
-project consumed ~$2,500-10,000 in compute, ~500-2,500 Wh of energy,
-and ~150-800g of CO2 across all sessions. Whether it produces enough
+project consumed ~$500-1,000 in compute, ~500-2,500 Wh of energy,
+and ~150-800g of CO2 across all sessions (3 tracked sessions account
+for ~295 Wh, ~95g CO2, ~$98). Whether it produces enough
 value to justify those costs is [an open question we are tracking](plans/measure-project-impact.md).
 
 ## Contributing