API Rate Limit Capacity Planner

Work out how many concurrent users or workers can call an API before you exceed its published rate limit. Enter the provider's quota, window size, average client load, and optional peak factors to receive a safe concurrency target.

Provider's published request quota for the window.
Duration of the rate limit window.
Average sustained load a single client generates.
Optional. Defaults to 1.0 to represent average load.
Optional. Defaults to 15% to leave headroom for spikes.

Planning guide only—confirm with provider documentation and live monitoring.

Examples

  • 900 requests, 60-second window, 12 requests/client/minute, 1.5× peak, 15% buffer ⇒ 42.50 clients
  • 1,200 requests, 120-second window, 8 requests/client/minute, defaults for optional fields ⇒ 63.75 clients

FAQ

How should I estimate requests per client?

Measure real traffic over several minutes during busy periods to capture sustained throughput rather than a single burst.

Can I model burst limits separately?

Yes—run a second scenario with the provider's burst cap or per-second limit to ensure your architecture respects both constraints.

What if capacity comes out fractional?

Round down to the nearest whole client or worker when provisioning so you stay within the safe range.

Additional Information

  • Limit per second equals allowed requests divided by window length; dividing by per-client demand reveals safe concurrency.
  • Peak multiplier inflates client demand to simulate traffic surges before applying the safety buffer.
  • Safety buffer subtracts a percentage of capacity so retries, jitter, or telemetry noise do not trigger HTTP 429 responses.

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