# Marseille, France → Seattle, USA RTT

🇫🇷 **Marseille, France (MRS)** → 🇺🇸 **Seattle, USA (SEA)**

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

During the 2026-08-16T04:07:28Z round, ICMP echo measurements from Marseille, France, to Seattle, USA, produced an average round-trip time of 141.7 ms over 50 samples, with a minimum of 135.29 ms and a maximum of 163.72 ms. Packet loss was zero and the route was rated Good for latency.

The 8,707.5 km great-circle distance has a theoretical fiber-floor RTT of 85.27 ms, placing the measured average at 1.66 times that floor and at 60.2% fiber efficiency. The wider gap above the fiber floor indicates the full path operates with more RTT overhead than the geometric minimum, though the 5.67 ms standard deviation and 4.70 ms jitter show the route stayed steady across the 50-sample window.

Ranked 11th among the 19 outbound routes from Marseille in the same round, this route's variability sat near the network-wide median standard-deviation-to-average ratio of 3.28%. The key metric for planners is the 141.7 ms average itself, a useful reference for Mediterranean-to-Pacific Northwest latency.

## Latency Summary

| Metric               | Value                                                        |
| -------------------- | ------------------------------------------------------------ |
| RTT                  | **141.7 ms**                                                 |
| Jitter               | **4.7 ms**                                                   |
| Packet Loss          | **0%**                                                       |
| Standard Fiber Floor | **85.27 ms**                                                 |
| Fiber Efficiency     | **60.2%**                                                    |
| Latency Tier         | Good                                                         |
| Source Region        | [Europe](/docs/network/latency/regions/europe)               |
| Destination Region   | [North America](/docs/network/latency/regions/north-america) |

## 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 [Marseille](https://www.geonames.org/2995469) (43.29695, 5.38107) and [Seattle](https://www.geonames.org/5809844) (47.60621, -122.33207). It does not disclose either facility address.

| Physical Reference                            | Value          |
| --------------------------------------------- | -------------- |
| WGS-84 geodesic distance                      | **8,707.5 km** |
| Vacuum RTT floor                              | **58.09 ms**   |
| Standard fiber RTT floor ($n_g=1.4679$)       | **85.27 ms**   |
| Low-latency fiber material floor              | **84.93 ms**   |
| Engineering floor (5% path allowance)         | **89.55 ms**   |
| Research 1.33× mapped-fiber reference         | **113.41 ms**  |
| Estimated unamplified path loss               | **1828.6 dB**  |
| Transparent optical spans / inline amplifiers | **115 / 114**  |
| Published RTT inflation over fiber floor      | **1.66×**      |

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        | **135.29 ms** |
| Average RTT        | **141.7 ms**  |
| Maximum RTT        | **163.72 ms** |
| Standard deviation | **5.67 ms**   |
| Stdev / average    | **4.0%**      |

## Route Context

* Departure PoP: [Marseille (MRS)](/docs/network/latency/mrs-marseille)
* Destination PoP: [Seattle (SEA)](/docs/network/latency/sea-seattle)
* Region overview: [Europe](/docs/network/latency/regions/europe) → [North America](/docs/network/latency/regions/north-america)
* Corridor overview: [Europe to North America](/docs/network/latency/regions/europe-to-north-america)
* 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**

* [Seattle to Marseille latency and RTT](/docs/network/latency/pairs/sea-mrs-rtt) — 141.2 ms

**Fastest routes departing Marseille (MRS)**

* [Marseille to Paris latency and RTT](/docs/network/latency/pairs/mrs-par-rtt) — 8.9 ms
* [Marseille to Frankfurt latency and RTT](/docs/network/latency/pairs/mrs-fra-rtt) — 16 ms
* [Marseille to London latency and RTT](/docs/network/latency/pairs/mrs-lon-rtt) — 18.9 ms
* [Marseille to Amsterdam latency and RTT](/docs/network/latency/pairs/mrs-ams-rtt) — 20.3 ms
* [Marseille to Berlin latency and RTT](/docs/network/latency/pairs/mrs-ber-rtt) — 20.6 ms

**Fastest routes arriving at Seattle (SEA)**

* [Los Angeles to Seattle latency and RTT](/docs/network/latency/pairs/lax-sea-rtt) — 26.9 ms
* [New York to Seattle latency and RTT](/docs/network/latency/pairs/nyc-sea-rtt) — 58.7 ms
* [Ashburn to Seattle latency and RTT](/docs/network/latency/pairs/iad-sea-rtt) — 62.3 ms
* [Miami to Seattle latency and RTT](/docs/network/latency/pairs/mia-sea-rtt) — 81.9 ms
* [Tokyo to Seattle latency and RTT](/docs/network/latency/pairs/tyo-sea-rtt) — 84.8 ms

**Same corridor (Europe → North America)**

* [London to New York latency and RTT](/docs/network/latency/pairs/lon-nyc-rtt) — 63.8 ms
* [Amsterdam to New York latency and RTT](/docs/network/latency/pairs/ams-nyc-rtt) — 68.6 ms
* [Paris to New York latency and RTT](/docs/network/latency/pairs/par-nyc-rtt) — 68.9 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/mrs-sea.pings.{csv,json,yaml}`. When citing, include the route, the measurement round timestamp, and the dataset version — for example: "Hats Network latency dataset, Marseille → Seattle 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/mrs-sea-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.