What is an API rate limit?

An API rate limit is a restriction on the number of requests a client can make to an API within a specified time window. It prevents abuse and ensures fair usage across all consumers.

How do I calculate the delay between requests?

Divide the time window (in milliseconds) by the number of allowed requests. For example, 60 requests per minute means 1,000ms (1 second) between each request.

What are X-RateLimit headers?

X-RateLimit-Limit, X-RateLimit-Remaining, X-RateLimit-Reset, and Retry-After are HTTP response headers that APIs use to communicate rate limit status to clients. This tool generates them for your API.

Yes. All calculations happen 100% in your browser. No data is ever sent to any server. The tool works entirely offline after the initial page load.

What API presets are available?

The tool includes presets for popular APIs like GitHub, Stripe, OpenAI, Twitter/X, Shopify, and more — each with their real published rate limits pre-filled.

Free Developer Tool

Plan Your API
Rate Limit Budget

Calculate requests per window, burst capacity, throttle delays, and generate rate limit headers — all in your browser, no data leaves your machine.

📊

Budget Calculator

Input your rate limits and see exactly how many requests you can make per second, minute, or hour.

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Throttle Delay

Calculate the optimal delay between requests to stay within limits without wasting capacity.

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Header Generator

Generate standard rate limit response headers (X-RateLimit-Limit, Retry-After, etc.) for your API.

Requests per Window

Window Duration (seconds)

Burst Size

Max requests allowed in a single burst

Target Utilization: 80%

Conservative (10%)Aggressive (100%)

⚡

13.33

Per Second

🕐

800.00

Per Minute

📊

48.0K

Per Hour

📅

1.2M

Per Day

Throttle Delay

75.0ms

Wait this long between requests to stay under the limit at 80% utilization

Burst Delay

750.0ms

Min delay when using burst capacity (100 burst / 1min window)

Frequently Asked Questions

Everything you need to know about API Rate Limit Calculator.

Plan Your APIRate Limit Budget

Budget Calculator

Throttle Delay

Header Generator

Frequently Asked Questions

Plan Your API
Rate Limit Budget