Networking
Latency Estimator
Estimate round‑trip time (RTT) from distance, or model request latency from RTT + DNS/TLS handshakes. Local only.
Inputs
Use the distance mode for a theoretical lower bound. Use the RTT model for a practical “how long will this request take?” estimate.
Light travels slower in glass than in vacuum (~2/3c). Real routes also take detours.
Result
Propagation-only estimate (lower bound).
Estimated RTT
10 ms
Practical RTTs are usually higher than propagation-only due to routing, queuing, and processing.
One-way (min)
5 ms
RTT (propagation)
10 ms
Practical lower bound
13 ms
What this tool estimates
Latency is mostly about round trips. Even tiny payloads can feel slow when RTT is high.
- Distance mode estimates propagation delay (speed-of-light limit).
- RTT model estimates request time from how many RTT steps occur (DNS, TCP, TLS, request/response).
How it works
Distance mode applies speed-of-light limits for the chosen medium to estimate RTT. Request mode multiplies your measured RTT by the number of round trips (DNS, TCP, TLS, request) plus server time.
- Real paths are longer than straight lines; expect higher RTT than the theoretical minimum.
- Large payloads can add transfer time; pair with the bandwidth calculator if data size matters.
Quick examples
Set TCP/TLS to 0 when reusing an existing connection.
Mini FAQ
Why is ping higher than distance math?
Routes zigzag through routers and queues, adding delay beyond straight-line propagation.
Distance vs request mode?
Use distance for a theoretical floor; request mode for end-to-end request timing.
How to reduce handshakes?
Reuse connections (keep-alive), prefer HTTP/2 or HTTP/3, and cache DNS.
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