If you're building with the Claude API, pricing will be one of your first questions. The good news: it's entirely token-based, predictable, and — with the right techniques — very affordable even at scale. This guide breaks down exactly what you'll pay and how to minimize it. How Claude API Pricing Works Claude charges per token — roughly 4 characters of English text. Every API call has two costs: Input tokens — your prompt, system message, and conversation history Output tokens — the model's response (typically 3–5× more expensive) Prices are listed per 1 million tokens (MTok). Claude Model Pricing (May 2025) ModelInput (per MTok)Output (per MTok)Best forClaude Haiku 4.5$0.80$4.00High-volume, simple tasksClaude Sonnet 4.6$3.00$15.00Balanced — most projectsClaude Opus 4.7$15.00$75.00Complex reasoning, low volume Rule of thumb: Start with Sonnet. Switch to Haiku for repetitive tasks (classification, extraction). Use Opus only when you need the extra reasoning power.…