ICMP RTT from Tokyo, Japan to Ashburn, USA: 142.9 ms average, 0% packet loss, and Good-tier stability from the 2026-08-16T04:07:28Z measurement.

🇯🇵 Tokyo, Japan (TYO) → 🇺🇸 Ashburn, USA (IAD)

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

In the 2026-08-16T04:07:28Z run, ICMP echo RTT between Tokyo, Japan and Ashburn, USA averaged 142.9 ms, with observed samples from 137.64 ms to 155.57 ms. All 50 probes returned successfully, so packet loss was 0%, and jitter was 3.66 ms.

The geodesic separation is 10,894.6 km, giving a theoretical fiber floor of 106.69 ms. At 142.9 ms, the measured average sits 1.34 times above that floor, with a fiber efficiency of 74.7% — a relatively tight fit between real-world round-trip time and the optical-path minimum.

Across the 19-route outbound set, this path is 8th by average RTT. Its variation around the average is roughly 3.4%, slightly above the 3.28% median for the outbound route set, but the min-max spread is only 17.93 ms and the measured latency tier is Good.

Latency Summary

Metric	Value
RTT	142.9 ms
Jitter	3.66 ms
Packet Loss	0%
Standard Fiber Floor	106.69 ms
Fiber Efficiency	74.7%
Latency Tier	Good
Source Region	Asia Pacific
Destination Region	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.

Ping series: TYO → IAD

50 ICMP echo samples at 100 ms intervals · round 2026-08-16T04:07:28Z · avg 142.9 ± 0.68 ms (SE)

Sample distribution: box = interquartile range (139.4–144.8 ms), median 141.1 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 (106.7 ms) for this route.

Full 50-sample dataset

Seq	Offset (ms)	RTT (ms)
1	0	140.37
2	100	139.72
3	200	141.14
4	300	138.80
5	400	141.29
6	500	140.50
7	600	140.88
8	700	140.62
9	800	138.23
10	900	138.29
11	1000	139.41
12	1100	141.39
13	1200	138.76
14	1300	141.14
15	1400	139.33
16	1500	141.34
17	1600	153.11
18	1700	143.53
19	1800	142.33
20	1900	138.83
21	2000	139.63
22	2100	141.12
23	2200	154.98
24	2300	143.89
25	2400	142.49
26	2500	139.01
27	2600	147.65
28	2700	144.53
29	2800	139.79
30	2900	139.10
31	3000	139.86
32	3100	142.56
33	3200	139.32
34	3300	138.93
35	3400	137.64
36	3500	140.76
37	3600	138.72
38	3700	138.12
39	3800	146.47
40	3900	152.75
41	4000	151.86
42	4100	146.22
43	4200	145.50
44	4300	155.28
45	4400	147.98
46	4500	144.87
47	4600	155.57
48	4700	145.99
49	4800	144.22
50	4900	141.18

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 Tokyo (35.68950, 139.69171) and Ashburn (39.04372, -77.48749). It does not disclose either facility address.

Physical Reference	Value
WGS-84 geodesic distance	10,894.6 km
Vacuum RTT floor	72.68 ms
Standard fiber RTT floor ( $n_g=1.4679$ )	106.69 ms
Low-latency fiber material floor	106.26 ms
Engineering floor (5% path allowance)	112.04 ms
Research 1.33× mapped-fiber reference	141.9 ms
Estimated unamplified path loss	2287.9 dB
Transparent optical spans / inline amplifiers	143 / 142
Published RTT inflation over fiber floor	1.34×

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	137.64 ms
Average RTT	142.9 ms
Maximum RTT	155.57 ms
Standard deviation	4.84 ms
Stdev / average	3.4%

RTT trend

Estimated route stability across the selected time window.

Average: 143.0 ms
Minimum: 141.6 ms
Maximum: 144.3 ms
Average loss: 0.01%

Route Context

Departure PoP: Tokyo (TYO)
Destination PoP: Ashburn (IAD)
Region overview: Asia Pacific → North America
Full global matrix: Backbone Latency Matrix
Physical methodology: Theoretical Fiber Latency

Reverse direction

Ashburn to Tokyo latency and RTT — 141.9 ms

Fastest routes departing Tokyo (TYO)

Tokyo to Taipei latency and RTT — 32.3 ms
Tokyo to Hong Kong latency and RTT — 44.8 ms
Tokyo to Singapore latency and RTT — 69.4 ms
Tokyo to Seattle latency and RTT — 84.8 ms
Tokyo to Los Angeles latency and RTT — 101.2 ms

Fastest routes arriving at Ashburn (IAD)

New York to Ashburn latency and RTT — 6 ms
Miami to Ashburn latency and RTT — 27.3 ms
Los Angeles to Ashburn latency and RTT — 60.4 ms
Seattle to Ashburn latency and RTT — 61.5 ms
London to Ashburn latency and RTT — 71 ms

Same corridor (Asia Pacific → North America)

Taipei to Seattle latency and RTT — 115.8 ms
Hong Kong to Seattle latency and RTT — 131.6 ms
Taipei to Los Angeles latency and RTT — 132 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/tyo-iad.pings.{csv,json,yaml}. When citing, include the route, the measurement round timestamp, and the dataset version — for example: "Hats Network latency dataset, Tokyo → Ashburn 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.

Tokyo, Japan → Ashburn, USA RTT