ICMP RTT from Seattle, USA to Sydney, Australia: average 161.3 ms, 0% packet loss, and route stability from round 2026-08-16T04:07:28Z.

🇺🇸 Seattle, USA (SEA) → 🇦🇺 Sydney, Australia (SYD)

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

The 2026-08-16T04:07:28Z ICMP echo measurement from Seattle to Sydney averaged 161.3 ms over 50 samples, with a minimum of 157.6 ms and a maximum of 177.48 ms. Zero packets were lost, and the standard deviation was only 3.32 ms with 2.66 ms jitter, making the route highly consistent; the max-min spread of 19.88 ms is notably narrow.

At a geodesic distance of 12,453.7 km, the vacuum round-trip floor is 83.08 ms and the fiber floor is 121.96 ms. The observed average sits 1.32 times above the fiber floor, for a fiber efficiency of 75.6%, reflecting how close the path comes to the straight-line fiber floor.

In the 19-route outbound context from Seattle, this path is ranked 16th. The median RTT scatter in the round is 3.28% of average RTT, while this route's scatter is only about 2.1% of its average, so the latency is relatively high but very stable.

Latency Summary

Metric	Value
RTT	161.3 ms
Jitter	2.66 ms
Packet Loss	0%
Standard Fiber Floor	121.96 ms
Fiber Efficiency	75.6%
Latency Tier	Fair
Source Region	North America
Destination Region	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.

Ping series: SEA → SYD

50 ICMP echo samples at 100 ms intervals · round 2026-08-16T04:07:28Z · avg 161.3 ± 0.47 ms (SE)

Sample distribution: box = interquartile range (159.2–162.6 ms), median 160.5 ms · whiskers = min–max · diamond = round average · each dot is one measured sample.

How to read this chart

The shaded band spans the measured minimum to maximum RTT of all samples collected up to that point, and the thin line traces the running average. The final position therefore matches the round statistics exactly — the band only widens when a new extreme sample arrives.

The dashed line is the round average, and the shaded band at the bottom is the theoretical fiber-optic floor (122.0 ms) for this route.

Full 50-sample dataset

Seq	Offset (ms)	RTT (ms)
1	0	177.48
2	100	164.40
3	200	159.67
4	300	159.26
5	400	161.30
6	500	161.72
7	600	164.59
8	700	164.45
9	800	162.98
10	900	159.17
11	1000	158.09
12	1100	159.47
13	1200	160.62
14	1300	165.49
15	1400	160.12
16	1500	159.28
17	1600	157.99
18	1700	161.51
19	1800	167.18
20	1900	162.63
21	2000	166.99
22	2100	162.58
23	2200	160.88
24	2300	159.09
25	2400	162.75
26	2500	159.87
27	2600	158.53
28	2700	159.76
29	2800	158.53
30	2900	162.27
31	3000	159.20
32	3100	157.78
33	3200	161.58
34	3300	158.59
35	3400	157.60
36	3500	164.51
37	3600	160.73
38	3700	160.44
39	3800	158.72
40	3900	158.08
41	4000	158.54
42	4100	159.90
43	4200	159.61
44	4300	161.84
45	4400	159.18
46	4500	162.33
47	4600	159.46
48	4700	163.64
49	4800	163.25
50	4900	161.37

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 for citation guidance.

Download this dataset

Per-route ICMP ping series, released under CC BY 4.0. Uncompressed plain text — no decompression step needed.

CSV JSON YAML Full dataset

Theoretical Fiber Latency

The public physical reference uses the GeoNames city centres for Seattle (47.60621, -122.33207) and Sydney (-33.86785, 151.20732). It does not disclose either facility address.

Physical Reference	Value
WGS-84 geodesic distance	12,453.7 km
Vacuum RTT floor	83.08 ms
Standard fiber RTT floor ( $n_g=1.4679$ )	121.96 ms
Low-latency fiber material floor	121.47 ms
Engineering floor (5% path allowance)	128.07 ms
Research 1.33× mapped-fiber reference	162.2 ms
Estimated unamplified path loss	2615.3 dB
Transparent optical spans / inline amplifiers	164 / 163
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.

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	157.6 ms
Average RTT	161.3 ms
Maximum RTT	177.48 ms
Standard deviation	3.32 ms
Stdev / average	2.1%

RTT trend

Estimated route stability across the selected time window.

Average: 161.1 ms
Minimum: 159.6 ms
Maximum: 162.7 ms
Average loss: 0.03%

Route Context

Departure PoP: Seattle (SEA)
Destination PoP: Sydney (SYD)
Region overview: North America → Asia Pacific
Corridor overview: North America to Asia Pacific
Full global matrix: Backbone Latency Matrix
Physical methodology: Theoretical Fiber Latency

Reverse direction

Sydney to Seattle latency and RTT — 161.9 ms

Fastest routes departing Seattle (SEA)

Seattle to Los Angeles latency and RTT — 25.9 ms
Seattle to New York latency and RTT — 59.5 ms
Seattle to Ashburn latency and RTT — 61.5 ms
Seattle to Miami latency and RTT — 81.7 ms
Seattle to Tokyo latency and RTT — 85 ms

Fastest routes arriving at Sydney (SYD)

Melbourne to Sydney latency and RTT — 9.8 ms
Singapore to Sydney latency and RTT — 94.5 ms
Tokyo to Sydney latency and RTT — 101.9 ms
Taipei to Sydney latency and RTT — 133.2 ms
Hong Kong to Sydney latency and RTT — 137.2 ms

Same corridor (North America → Asia Pacific)

Los Angeles to Tokyo latency and RTT — 101.2 ms
Seattle to Taipei latency and RTT — 114.7 ms
Seattle to Hong Kong latency and 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. Per-pair files are available at /opendata/latency/latest/pairs/sea-syd.pings.{csv,json,yaml}. When citing, include the route, the measurement round timestamp, and the dataset version — for example: "Hats Network latency dataset, Seattle → Sydney round 2026-08-16T04:07:28Z, CC BY 4.0".

Data auto-generated on August 16, 2026. Explore the full interactive latency matrix or browse more city-pair routes.

Seattle, USA → Sydney, Australia RTT