Kimi K3 token cost is not just input plus output. A realistic estimate includes cache behavior, request volume, and retries.
Count every input source
Input tokens can include the visible user prompt, system instructions, files, prior turns, retrieval results, and tool output. For coding agents, hidden context often dominates the visible prompt.
Create a few presets for your common workloads: small chat, coding agent, repository review, document batch, and evaluation run.
Estimate output honestly
Long answers, generated code, summaries, tables, and repeated explanations all add output tokens. If output is the expensive part of your provider's rate card, response style can drive the bill.
Ask for diffs, concise summaries, or structured fields when you do not need full prose.
Add retries before launch
A strong model still gets follow-up requests. Users clarify requirements, tools fail, and code edits need repair. Add retry overhead before the first invoice proves you needed it.
After launch, compare real logs with your estimates and update the calculator monthly.