Rate Limit Calculator
Calculate effective API throughput based on RPM and TPM limits
Configuration
Token-limited: TPM (2,00,000) constrains you to 200 RPM at 1000 tokens/request. Consider reducing prompt size or upgrading tier.
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What Are API Rate Limits?
API rate limits control how many requests you can make to an AI service within a given time period. LLM providers like OpenAI, Anthropic, and Google enforce two types of limits: requests per minute (RPM) and tokens per minute (TPM). Understanding these limits is essential for building reliable, production-grade AI applications.
This rate limit calculator helps you determine your effective throughput based on your account tier and average request size. It identifies whether you're constrained by request count or token volume, helping you optimize your API usage strategy.
Understanding Rate Limit Types
RPM (Requests Per Minute)
Limits the number of API calls regardless of size. A 10-token request counts the same as a 10,000-token request.
TPM (Tokens Per Minute)
Limits total tokens processed (input + output) per minute. Large prompts and completions consume capacity faster.
Effective RPM
Your actual throughput is the lower of RPM limit and TPM-derived requests. This calculator shows which one bottlenecks you.
Rate Limits by Provider and Tier
| Provider | Tier | RPM | TPM |
|---|---|---|---|
| OpenAI | Free | 3 | 40,000 |
| OpenAI | Tier 2 | 5,000 | 2,000,000 |
| Anthropic | Tier 1 | 50 | 40,000 |
| Tier 1 | 60 | 60,000 |
Limits are approximate and may vary. Check provider documentation for current values.
Rate Limit Optimization Tips
- Batch requests: Combine multiple small requests into one larger request to maximize TPM utilization.
- Implement queuing: Use a request queue with rate limiting to smooth out traffic spikes.
- Add exponential backoff: When hitting limits, wait and retry with increasing delays.
- Monitor usage: Track your RPM and TPM consumption to identify patterns and bottlenecks.
- Request tier upgrades: If you consistently hit limits, request a higher tier from your provider.
Frequently Asked Questions
What happens when I hit a rate limit?
The API returns a 429 error (Too Many Requests) with a Retry-After header indicating when to retry. Implement proper error handling to pause and retry.
How do I increase my rate limits?
Rate limits increase with usage and spending. OpenAI auto-upgrades tiers as you spend more. Anthropic and Google may require contacting support for enterprise limits.
Are rate limits per API key or per organization?
Typically per organization. Multiple API keys under the same organization share rate limits, so creating new keys won't increase your throughput.