# São Paulo, Brazil → Ashburn, USA RTT

🇧🇷 **São Paulo, Brazil (GRU)** → 🇺🇸 **Ashburn, USA (IAD)**

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

For the 2026-08-16T04:07:28Z round, the São Paulo-to-Ashburn ICMP path averaged 128 ms, with a minimum of 121.55 ms and maximum of 142 ms across 50 samples. Packet loss was zero and jitter was 4.04 ms.

The observed RTT sits about 1.71 times above the theoretical fiber floor of roughly 74.8 ms for the 7,637.7 km distance, corresponding to 58.4% fiber efficiency. This route ranked third among the 19 outbound routes measured in the round, a strong standing for a North American destination.

Although the average latency is steady, the standard deviation of 4.73 ms is about 3.7% of the average, slightly above the median variation of roughly 3.3% across those 19 routes. The combination of zero loss, low jitter, and a tight 121.55–142 ms range makes for a generally stable path with only modest variation near the upper bound.

## Latency Summary

| Metric               | Value                                                        |
| -------------------- | ------------------------------------------------------------ |
| RTT                  | **128 ms**                                                   |
| Jitter               | **4.04 ms**                                                  |
| Packet Loss          | **0%**                                                       |
| Standard Fiber Floor | **74.79 ms**                                                 |
| Fiber Efficiency     | **58.4%**                                                    |
| Latency Tier         | Good                                                         |
| Source Region        | [South America](/docs/network/latency/regions/south-america) |
| 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 [São Paulo](https://www.geonames.org/3448439) (-23.54750, -46.63611) and [Ashburn](https://www.geonames.org/4744870) (39.04372, -77.48749). It does not disclose either facility address.

| Physical Reference                            | Value          |
| --------------------------------------------- | -------------- |
| WGS-84 geodesic distance                      | **7,637.7 km** |
| Vacuum RTT floor                              | **50.95 ms**   |
| Standard fiber RTT floor ($n_g=1.4679$)       | **74.79 ms**   |
| Low-latency fiber material floor              | **74.49 ms**   |
| Engineering floor (5% path allowance)         | **78.54 ms**   |
| Research 1.33× mapped-fiber reference         | **99.48 ms**   |
| Estimated unamplified path loss               | **1603.9 dB**  |
| Transparent optical spans / inline amplifiers | **101 / 100**  |
| Published RTT inflation over fiber floor      | **1.71×**      |

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        | **121.55 ms** |
| Average RTT        | **128 ms**    |
| Maximum RTT        | **142 ms**    |
| Standard deviation | **4.73 ms**   |
| Stdev / average    | **3.7%**      |

## Route Context

* Departure PoP: [São Paulo (GRU)](/docs/network/latency/gru-sao-paulo)
* Destination PoP: [Ashburn (IAD)](/docs/network/latency/iad-ashburn)
* Region overview: [South America](/docs/network/latency/regions/south-america) → [North America](/docs/network/latency/regions/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**

* [Ashburn to São Paulo latency and RTT](/docs/network/latency/pairs/iad-gru-rtt) — 101.4 ms

**Fastest routes departing São Paulo (GRU)**

* [São Paulo to Miami latency and RTT](/docs/network/latency/pairs/gru-mia-rtt) — 74 ms
* [São Paulo to New York latency and RTT](/docs/network/latency/pairs/gru-nyc-rtt) — 122 ms
* [São Paulo to Los Angeles latency and RTT](/docs/network/latency/pairs/gru-lax-rtt) — 130.8 ms
* [São Paulo to Seattle latency and RTT](/docs/network/latency/pairs/gru-sea-rtt) — 155.9 ms
* [São Paulo to London latency and RTT](/docs/network/latency/pairs/gru-lon-rtt) — 175.8 ms

**Fastest routes arriving at Ashburn (IAD)**

* [New York to Ashburn latency and RTT](/docs/network/latency/pairs/nyc-iad-rtt) — 6 ms
* [Miami to Ashburn latency and RTT](/docs/network/latency/pairs/mia-iad-rtt) — 27.3 ms
* [Los Angeles to Ashburn latency and RTT](/docs/network/latency/pairs/lax-iad-rtt) — 60.4 ms
* [Seattle to Ashburn latency and RTT](/docs/network/latency/pairs/sea-iad-rtt) — 61.5 ms
* [London to Ashburn latency and RTT](/docs/network/latency/pairs/lon-iad-rtt) — 71 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/gru-iad.pings.{csv,json,yaml}`. When citing, include the route, the measurement round timestamp, and the dataset version — for example: "Hats Network latency dataset, São Paulo → Ashburn 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/gru-iad-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.