How I Cut My Claude Code Bill by 60% Without Losing Productivity

My first full month using Claude Code on a Kotlin Multiplatform project cost me $340. My second month? $127. Same project. Same velocity. Same output quality. The difference was understanding where tokens actually go — and stopping the bleeding at the source. This isn't about using Claude Code less. It's about using it smarter. Here are the strategies that made the difference, with real numbers from my workflow. The Hidden Cost: Context Window Bloat The biggest cost driver isn't how many prompts you send. It's how much context you carry in each one. Every message in a Claude Code session includes the full conversation history. By message 30 in a session, you're sending 30 previous exchanges plus your new prompt — and paying for every token. I tracked my sessions for a week. The pattern was clear: Session Length Avg Cost Per Prompt Total Session Cost 1-10 messages $0.08 $0.50 11-25 messages $0.35 $6.50 26-50 messages $0.90 $28.00 50+ messages $1.80 $72.00+ The cost per prompt increases