diff --git a/llm/gem/gem.go b/llm/gem/gem.go
index 178df68..1621f2d 100644
--- a/llm/gem/gem.go
+++ b/llm/gem/gem.go
@@ -431,14 +431,9 @@
 		}
 	}
 
-	// For Gemini 2.5 Pro Preview pricing: $1.25 per 1M input tokens, $10 per 1M output tokens
-	// Convert to dollars
-	costUSD := float64(inputTokens)*1.25/1_000_000.0 + float64(outputTokens)*10/1_000_000.0
-
 	return llm.Usage{
 		InputTokens:  inputTokens,
 		OutputTokens: outputTokens,
-		CostUSD:      costUSD,
 	}
 }
 
@@ -573,6 +568,7 @@
 	ensureToolIDs(content)
 
 	usage := calculateUsage(gemReq, gemRes)
+	usage.CostUSD = llm.CostUSDFromResponse(gemRes.Header())
 
 	stopReason := llm.StopReasonEndTurn
 	for _, part := range content {