# Seattle, USA → Melbourne, Australia RTT

🇺🇸 **Seattle, USA (SEA)** → 🇦🇺 **Melbourne, Australia (MEL)**

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

The 2026-08-16T04:07:28Z ICMP echo measurement from Seattle to Melbourne averaged 170.1 ms over 50 samples, with a minimum of 164.93 ms and a maximum of 189.47 ms. Zero packets were lost, and the standard deviation of 4.46 ms with 3.88 ms jitter indicates a steady path; the max-min spread of 24.54 ms is narrow for a route in the Fair latency tier.

At a geodesic distance of 13,166 km, the vacuum round-trip floor is 87.83 ms and the fiber floor is 128.93 ms. The observed average sits 1.32 times above the fiber floor, for a fiber efficiency of 75.8%, meaning the route carries noticeable overhead beyond the straight-line fiber path.

In the 19-route outbound context from Seattle, this path is ranked 18th. The median RTT scatter across outbound routes in the round is 3.28% of average RTT, while this route's scatter is only about 2.6% of its average, so it is steadier than the typical route even though its absolute latency is relatively high.

## Latency Summary

| Metric               | Value                                                        |
| -------------------- | ------------------------------------------------------------ |
| RTT                  | **170.1 ms**                                                 |
| Jitter               | **3.88 ms**                                                  |
| Packet Loss          | **0%**                                                       |
| Standard Fiber Floor | **128.93 ms**                                                |
| Fiber Efficiency     | **75.8%**                                                    |
| Latency Tier         | Fair                                                         |
| Source Region        | [North America](/docs/network/latency/regions/north-america) |
| Destination Region   | [Asia Pacific](/docs/network/latency/regions/asia-pacific)   |

## 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 [Seattle](https://www.geonames.org/5809844) (47.60621, -122.33207) and [Melbourne](https://www.geonames.org/2158177) (-37.81400, 144.96332). It does not disclose either facility address.

| Physical Reference                            | Value         |
| --------------------------------------------- | ------------- |
| WGS-84 geodesic distance                      | **13,166 km** |
| Vacuum RTT floor                              | **87.83 ms**  |
| Standard fiber RTT floor ($n_g=1.4679$)       | **128.93 ms** |
| Low-latency fiber material floor              | **128.41 ms** |
| Engineering floor (5% path allowance)         | **135.4 ms**  |
| Research 1.33× mapped-fiber reference         | **171.48 ms** |
| Estimated unamplified path loss               | **2764.9 dB** |
| Transparent optical spans / inline amplifiers | **173 / 172** |
| Published RTT inflation over fiber floor      | **1.32×**     |

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        | **164.93 ms** |
| Average RTT        | **170.1 ms**  |
| Maximum RTT        | **189.47 ms** |
| Standard deviation | **4.46 ms**   |
| Stdev / average    | **2.6%**      |

## Route Context

* Departure PoP: [Seattle (SEA)](/docs/network/latency/sea-seattle)
* Destination PoP: [Melbourne (MEL)](/docs/network/latency/mel-melbourne)
* Region overview: [North America](/docs/network/latency/regions/north-america) → [Asia Pacific](/docs/network/latency/regions/asia-pacific)
* Corridor overview: [North America to Asia Pacific](/docs/network/latency/regions/north-america-to-asia-pacific)
* 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**

* [Melbourne to Seattle latency and RTT](/docs/network/latency/pairs/mel-sea-rtt) — 172.1 ms

**Fastest routes departing Seattle (SEA)**

* [Seattle to Los Angeles latency and RTT](/docs/network/latency/pairs/sea-lax-rtt) — 25.9 ms
* [Seattle to New York latency and RTT](/docs/network/latency/pairs/sea-nyc-rtt) — 59.5 ms
* [Seattle to Ashburn latency and RTT](/docs/network/latency/pairs/sea-iad-rtt) — 61.5 ms
* [Seattle to Miami latency and RTT](/docs/network/latency/pairs/sea-mia-rtt) — 81.7 ms
* [Seattle to Tokyo latency and RTT](/docs/network/latency/pairs/sea-tyo-rtt) — 85 ms

**Fastest routes arriving at Melbourne (MEL)**

* [Sydney to Melbourne latency and RTT](/docs/network/latency/pairs/syd-mel-rtt) — 9.8 ms
* [Singapore to Melbourne latency and RTT](/docs/network/latency/pairs/sin-mel-rtt) — 88.6 ms
* [Tokyo to Melbourne latency and RTT](/docs/network/latency/pairs/tyo-mel-rtt) — 113.9 ms
* [Hong Kong to Melbourne latency and RTT](/docs/network/latency/pairs/hkg-mel-rtt) — 138.4 ms
* [Taipei to Melbourne latency and RTT](/docs/network/latency/pairs/tpe-mel-rtt) — 142 ms

**Same corridor (North America → Asia Pacific)**

* [Los Angeles to Tokyo latency and RTT](/docs/network/latency/pairs/lax-tyo-rtt) — 101.2 ms
* [Seattle to Taipei latency and RTT](/docs/network/latency/pairs/sea-tpe-rtt) — 114.7 ms
* [Seattle to Hong Kong latency and RTT](/docs/network/latency/pairs/sea-hkg-rtt) — 130.4 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/sea-mel.pings.{csv,json,yaml}`. When citing, include the route, the measurement round timestamp, and the dataset version — for example: "Hats Network latency dataset, Seattle → Melbourne 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/sea-mel-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.