LLM Latency Calculator
Find the tokens/sec needed to hit a latency target.
Results update automatically as you type.
Result
Need ~192 tokens/sec
to return 500 tokens within 3s
- Target latency
- 3 s
- Time to first token
- 400 ms
- Output tokens
- 500 tokens
- Required speed
- 192 tok/s
Have a latency budget? Enter your target response time, output length and time-to-first-token to see how fast the model must generate tokens.
How this is calculated
This calculator uses the infrastructure 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
Need ~192 tokens/sec
to return 500 tokens within 3s
- Target latency
- 3 s
- Time to first token
- 400 ms
- Output tokens
- 500 tokens
- Required speed
- 192 tok/s
Frequently asked questions
Why does output length affect latency?+
Tokens are generated sequentially, so more output means more time at a given tokens-per-second rate.
How do I reduce latency?+
Cap output length, stream responses, pick faster models, and reduce time-to-first-token with warm instances.