RTT
Round-trip time is the measured form of latency between two endpoints, covering both directions of the path.
Definitions only — a term explained here is not a service we sell.
Round-trip time is latency as measured: send, wait, receive. It covers both legs, so it is larger than the one-way delay, and splitting the path into browser-to-PoP and PoP-side legs shows what to fix.
Reading a round trip
40 ms
| Value | What it means |
|---|---|
| 1 ms | Same metro |
| 10 ms | Regional path |
| 40 ms | Regional path |
| 120 ms | Intercontinental path |
| 300 ms | Queues or a long path |
| 800 ms | Queues or a long path |
Text description
The ruler plots round-trip time on a scale from 1 to 1000 milliseconds. Short metro paths sit low, regional and intercontinental paths in the middle, and queues or long paths high. A round trip covers both directions, so each mark describes a path and a moment.
What to check
Measure with the same payload and protocol as the real traffic. Warm up the connection, because the first request pays DNS, TCP and TLS costs. Test both directions, and look at the 95th percentile and jitter rather than the mean. The latency tool reports segments.