API Rate Limiting Calculator
Derive per-client rate limits from real traffic math and export nginx/Express config
Work out sensible rate limits for your API by modeling expected traffic, burst behavior, and the capacity you want to protect. It helps you choose limits that keep the service stable for everyone without throttling legitimate users.
How to use API Rate Limiting Calculator
- Enter your expected request volume and burst patterns.
- Set the capacity or fairness goals you want to enforce.
- Calculate recommended rate-limit thresholds.
- Apply the limits in your gateway or middleware.
Frequently asked questions
What's the difference between rate and burst limits?
A rate limit caps sustained requests over time (e.g., per minute), while a burst allowance permits short spikes above that rate. Together they balance fairness and flexibility.
Which algorithm should I use to enforce limits?
Token bucket and leaky bucket are common choices: token bucket allows controlled bursts, while fixed or sliding windows are simpler to reason about. Pick based on your traffic shape.
How do I avoid throttling real users?
Set limits above typical legitimate usage with headroom for bursts, and apply them per client or API key so one heavy user doesn't affect others.
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