example in linked billing for rate limit explains it https://support.cloudflare.com/hc/en-us/articles/115000272247-Billing-for-Cloudflare-Rate-Limiting
For example, given a rule that matches example.com/ratelimit/* and blocks clients that send over 30 requests per minute:
Client A sends 20,000 requests to example.com/ratelimit/foo at a rate of 10 requests per minute. All requests are allowed.
Client B sends 80,000 requests to example.com/ratelimit/bar, usually at a rate of 10 requests per minute, but with bursts over 30 requests per minute. 50,000 of their requests are blocked during the bursts, and 30,000 are allowed when their request rate is lower.
Client C sends 20,000 requests to example.com/elsewhere at a rate of 40 requests per minute. While this exceeds the theshold, it doesn’t match the rule path, so all 20,000 requests are allowed.
In this example, 50,000 requests are billable: clients A and B both sent requests that matched the rule, but some of client B’s request were blocked, and those blocked requests were billed. In total, the cost is (50,000 - 10,000) * $0.05 = $0.20.
whoops i re-read that and says blocked requests are billed not allowed requests but the first part of explanation says good allowed requests so contradicting each other LOL
What is billable for Rate Limiting?
Rate Limiting is billed based on the number of good (not blocked) requests that match your defined rules across all your websites. Each request is only counted once so you will not be double charged if a request matches multiple rules.
blocked requests make sense, but billed on allowed good requests would be insanely expensive