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Start with the guided AI Agent Token Waste Audit
Find repeated context, retry loops, routing waste, fallback waste, and oversized prompts before estimating exact costs.
Context Calculator
LLM Context Window Calculator
Know how much conversation space you have left after your system prompt.
Last updated: May 2026
Your Inputs
Count characters in your system prompt (copy and check in a text editor).
Results
System prompt tokens (approx)
500
2000 chars ÷ 4
Available context after system prompt
255,500
99.8% of total window
Tokens per conversation turn
325
500+800 chars ÷ 4
Remaining tokens for conversation
253,875
Est. turns fitting before limit
786
Approximate; actual varies by provider
System prompt % of context
0.2%
Above 30% may limit conversation length
Disclaimer:All cost estimates are approximate and based on public API pricing. Actual costs depend on your contract rate, usage patterns, and provider pricing changes. This tool does not constitute financial, legal, tax, or operational advice. Verify pricing with your AI provider's official pricing page.
Assumptions & Limitations
- Uses 4 chars/token approximation; actual varies by model and content.
- Does not account for tokenizer overhead or special formatting tokens.
- 80% threshold is a practical guideline, not a hard limit.