Chat History Token Growth Calculator
See how resending chat history inflates tokens and cost.
Results update automatically as you type.
Result
70,300 tokens sent by message 20
Full history costs $0.0135/session · a 6-turn window costs $0.00904
- Total input tokens (full history)
- 70,300 tokens
- Session cost — full history
- $0.0135
- Session cost — 6-turn window
- $0.00904
- Saved by windowing
- $0.00450
In a chatbot, every turn usually resends the whole conversation — so cost grows with each message. See how many tokens you're sending by the last message and how much a sliding window would save.
How this is calculated
This calculator uses the tokens formulas described in our methodology. All figures are estimates for planning; verify current pricing with each provider before relying on them.
Worked example (defaults)
With the default inputs above, here is the result:
Result
70,300 tokens sent by message 20
Full history costs $0.0135/session · a 6-turn window costs $0.00904
- Total input tokens (full history)
- 70,300 tokens
- Session cost — full history
- $0.0135
- Session cost — 6-turn window
- $0.00904
- Saved by windowing
- $0.00450
Frequently asked questions
Why does chat cost grow over time?+
Each new turn typically includes the full prior conversation as input, so input tokens (and cost) grow with every message.
How do I control it?+
Use a sliding window of recent turns, summarize old history, or cache the system prompt.