Tools

Eight calculators, each computing from your actual numbers rather than a vendor's marketing example. Every one runs entirely in your browser — no usage data you enter is transmitted anywhere — and every result is URL-encoded, so you can copy a link to a specific calculation and it will reproduce exactly, which makes a result shareable in a Slack thread or a PR description instead of something you'd have to re-describe from scratch.

Start with the subscription vs API cost calculator if you're deciding between a flat plan and metered billing — it's the tool that started this site, and the one most readers arrive looking for. If you already know you're on the API and want to reduce the bill, the prompt-caching savings calculator and the batch vs realtime calculator are the two levers most integrations leave unused, often because nobody on the team has sat down and worked out whether the request pattern actually qualifies.

If you're choosing a model for a new task, the model picker walks the trade-off rather than asserting a single "best" answer, because for most workloads there genuinely isn't one — the right model depends on how intelligence-sensitive the task is against how much of the cost curve you can absorb. Once you're in production, the usage tracker and the context-window planner are the two tools worth bookmarking for ongoing use rather than a one-time decision.