Requests Per Second (RPS) measures how many requests your system processes each second. For API and backend teams, this is one of the fastest ways to reason about expected load.
Core Formula
In practical test planning, a common estimate is:
cycle_seconds = think_time + (response_time_ms / 1000)
RPS = (users * requests_per_flow) / cycle_seconds
This gives a baseline estimate for expected throughput under a given user behavior profile.
Why It Matters
- It helps align QA, SRE, and backend on realistic targets.
- It supports infrastructure planning before expensive tests.
- It makes performance regressions easier to identify over time.
Common Mistake
Teams often compare raw RPS numbers without matching latency assumptions. If one scenario has 120 ms and another has 450 ms, direct comparison is misleading.
Use RPS together with p95/p99 latency and error rate.
Next Step
Use the RPS Calculator to simulate your own numbers and share a scenario link with your team.