API Rate Limit Calculator – Requests and Throttling
Calculate API usage against rate limits and find optimal request batching.
About This Calculator
Calculate API usage against rate limits and find optimal request batching. Use the calculator above for instant results.
Worked Examples
- Utilization: 80% | Headroom: 20 req/min
- Min delay: 600ms between requests
Answer: 80% utilized
- Utilization: 5% | Plenty of headroom
Answer: 5% — plenty of headroom
- 150% utilization — WILL BE THROTTLED
- Implement queuing or batching
Answer: Need to queue/batch requests
Who Uses This Calculator?
Plan API usage against limits.
Manage third-party API consumption.
Rate limiting implementation planning.
Understand API tier requirements.
Common Mistakes to Avoid
❌ Rate limits are usually per-key, not per-IP
Most APIs rate limit by API key. Multiple keys can multiply your effective rate limit (if ToS allows).
❌ Retry with exponential backoff
When hitting rate limits, retry after exponential delay: 1s, 2s, 4s, 8s... with jitter. Never retry immediately.
Frequently Asked Questions
Common API rate limits?
Twitter API: 300 req/15min. Stripe: 100 req/sec. OpenAI: varies by tier. Salesforce: 5,000-1M req/day. GitHub: 5,000 req/hour authenticated.
Stay under 70% of limit?
Buffer for burst traffic. If you're at 80%+ consistently, upgrade to higher-tier plan before you start seeing throttling.
Rate limit strategies?
Queue requests. Batch where possible. Cache responses. Use webhooks instead of polling. Upgrade API tier.