# London, UK → Frankfurt, Germany RTT

🇬🇧 **London, UK (LON)** → 🇩🇪 **Frankfurt, Germany (FRA)**

Measurement round: `2026-08-16T04:07:28Z`.

In round 2026-08-16T04:07:28Z, ICMP echo round-trip time from London, UK to Frankfurt, Germany averaged 13.6 ms across 50 samples, with a minimum of 13.18 ms and a maximum of 15.43 ms. No packets were lost, and jitter was 0.29 ms.

The geodesic distance of 639.5 km yields a fiber-floor round-trip estimate of 6.26 ms. The observed 13.6 ms average is 2.17 times that floor, corresponding to 46.1% fiber efficiency; the 13.18 ms minimum remains 6.92 ms above the floor, so the route does not approach its physical limit in this round.

This route ranked third among the 19 routes measured from London in this round. Its standard deviation of 0.42 ms is about 3.1% of the mean, close to the 3.28% median spread across the set, and jitter stayed at 0.29 ms. Despite the modest fiber-efficiency figure, the route shows tight dispersion within the ultra-low latency tier.

## Latency Summary

| Metric               | Value                                          |
| -------------------- | ---------------------------------------------- |
| RTT                  | **13.6 ms**                                    |
| Jitter               | **0.29 ms**                                    |
| Packet Loss          | **0%**                                         |
| Standard Fiber Floor | **6.26 ms**                                    |
| Fiber Efficiency     | **46.1%**                                      |
| Latency Tier         | Ultra-Low                                      |
| Source Region        | [Europe](/docs/network/latency/regions/europe) |
| Destination Region   | [Europe](/docs/network/latency/regions/europe) |

## Ping Measurement Series

The chart below renders the 50-sample ICMP echo measurement round for this route; an accessible table of every sample is included with the chart.

## Download This Route's Data

This route's measurement round is published as open data (CC BY 4.0) in CSV, JSON, and YAML. See [About This Measurement](#about-this-measurement) for citation guidance.

## Theoretical Fiber Latency

The public physical reference uses the GeoNames city centres for [London](https://www.geonames.org/2643743) (51.50853, -0.12574) and [Frankfurt am Main](https://www.geonames.org/2925533) (50.11552, 8.68417). It does not disclose either facility address.

| Physical Reference                            | Value        |
| --------------------------------------------- | ------------ |
| WGS-84 geodesic distance                      | **639.5 km** |
| Vacuum RTT floor                              | **4.27 ms**  |
| Standard fiber RTT floor ($n_g=1.4679$)       | **6.26 ms**  |
| Low-latency fiber material floor              | **6.24 ms**  |
| Engineering floor (5% path allowance)         | **6.58 ms**  |
| Research 1.33× mapped-fiber reference         | **8.33 ms**  |
| Estimated unamplified path loss               | **134.3 dB** |
| Transparent optical spans / inline amplifiers | **9 / 8**    |
| Published RTT inflation over fiber floor      | **2.17×**    |

Attenuation is used to estimate the number of 80 km optical spans; it does not directly slow light. See the full [theoretical fiber latency, GeoNames, attenuation, and amplifier methodology](/docs/network/latency/theoretical-fiber-latency).

## Stability & Trend

The current measurement round (2026-08-16T04:07:28Z) collected 50 ICMP echo samples on this route. Distribution statistics from that round:

| Round Statistic    | Value        |
| ------------------ | ------------ |
| Minimum RTT        | **13.18 ms** |
| Average RTT        | **13.6 ms**  |
| Maximum RTT        | **15.43 ms** |
| Standard deviation | **0.42 ms**  |
| Stdev / average    | **3.1%**     |

## Route Context

* Departure PoP: [London (LON)](/docs/network/latency/lon-london)
* Destination PoP: [Frankfurt (FRA)](/docs/network/latency/fra-frankfurt)
* Region overview: [Europe](/docs/network/latency/regions/europe) → [Europe](/docs/network/latency/regions/europe)
* Full global matrix: [Backbone Latency Matrix](/docs/network/latency)
* Physical methodology: [Theoretical Fiber Latency](/docs/network/latency/theoretical-fiber-latency)

## Related City-Pair Routes

**Reverse direction**

* [Frankfurt to London latency and RTT](/docs/network/latency/pairs/fra-lon-rtt) — 12.9 ms

**Fastest routes departing London (LON)**

* [London to Amsterdam latency and RTT](/docs/network/latency/pairs/lon-ams-rtt) — 5.2 ms
* [London to Paris latency and RTT](/docs/network/latency/pairs/lon-par-rtt) — 6.4 ms
* [London to Berlin latency and RTT](/docs/network/latency/pairs/lon-ber-rtt) — 16.2 ms
* [London to Marseille latency and RTT](/docs/network/latency/pairs/lon-mrs-rtt) — 17.9 ms
* [London to Moscow latency and RTT](/docs/network/latency/pairs/lon-mow-rtt) — 43.5 ms

**Fastest routes arriving at Frankfurt (FRA)**

* [Amsterdam to Frankfurt latency and RTT](/docs/network/latency/pairs/ams-fra-rtt) — 5.9 ms
* [Berlin to Frankfurt latency and RTT](/docs/network/latency/pairs/ber-fra-rtt) — 6.1 ms
* [Paris to Frankfurt latency and RTT](/docs/network/latency/pairs/par-fra-rtt) — 7.6 ms
* [Marseille to Frankfurt latency and RTT](/docs/network/latency/pairs/mrs-fra-rtt) — 16 ms
* [Moscow to Frankfurt latency and RTT](/docs/network/latency/pairs/mow-fra-rtt) — 35.9 ms

**Same corridor (Europe → Europe)**

* [Amsterdam to London latency and RTT](/docs/network/latency/pairs/ams-lon-rtt) — 5.2 ms
* [Frankfurt to Amsterdam latency and RTT](/docs/network/latency/pairs/fra-ams-rtt) — 5.9 ms
* [Frankfurt to Berlin latency and RTT](/docs/network/latency/pairs/fra-ber-rtt) — 6.1 ms

## About This Measurement

Published RTT reflects best-case backbone path behavior measured with ICMP echo probes between PoPs. End-user latency also depends on local access networks, congestion, routing policy, and traffic engineering. None of these values is an SLA.

The measurement round behind this page is published as open data under **CC BY 4.0** in the [Hats Network latency dataset](/opendata/latency/). Per-pair files are available at `/opendata/latency/latest/pairs/lon-fra.pings.{csv,json,yaml}`. When citing, include the route, the measurement round timestamp, and the dataset version — for example: "Hats Network latency dataset, London → Frankfurt round 2026-08-16T04:07:28Z, CC BY 4.0".

***

*Data auto-generated on August 16, 2026. Explore the [full interactive latency matrix](/docs/network/latency) or browse more [city-pair routes](/docs/network/latency/pairs).*

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## License and attribution

- **Canonical source:** [View the human-readable HTML page](https://hatsnet.io/docs/network/latency/pairs/lon-fra-rtt).
- **Original documentation:** © Hats Network Inc., licensed under [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0/).
- **Public latency data:** © Hats Network Inc., licensed under [CC BY 4.0](https://creativecommons.org/licenses/by/4.0/).
- **Full terms:** [Content and Data License](https://hatsnet.io/docs/legal/content-and-data-license) — includes attribution requirements, third-party material, trademarks, source code and other exclusions.