Tokyo to London ICMP RTT measurement: average latency, jitter, packet loss, route distance, and stability data for Japan-UK connectivity.

🇯🇵 Tokyo, Japan (TYO) → 🇬🇧 London, UK (LON)

Measurement round: 2026-08-15T04:03:13Z.

In measurement round 2026-08-15T04:03:13Z, 50 ICMP echo probes from Tokyo to London returned an average round-trip time of 204.3 ms, with a minimum of 192.9 ms, a maximum of 228.54 ms, and no packet loss.

This path placed 16th among the 19 outbound routes measured from Tokyo in the same round, and its standard deviation of 8.36 ms is about 4.1% of the average, above the network median ratio of 3.08% for those routes.

Relative to the 9,582 km great-circle distance, the theoretical fiber floor is 93.84 ms; the observed average sits 2.18 times that floor, a 45.9% fiber efficiency figure. The 7.5 ms jitter and zero loss confirm a fairly consistent path, though the distance-adjusted overhead remains substantial.

Latency Summary

Metric	Value
RTT	204.3 ms
Jitter	7.5 ms
Packet Loss	0%
Standard Fiber Floor	93.84 ms
Fiber Efficiency	45.9%
Latency Tier	Fair
Source Region	Asia Pacific
Destination Region	Europe

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 → LON

50 ICMP echo samples at 100 ms intervals · round 2026-08-15T04:03:13Z · avg 204.3 ± 1.18 ms (SE)

Sample distribution: box = interquartile range (198.2–209.2 ms), median 202.2 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 (93.8 ms) for this route.

Full 50-sample dataset

Seq	Offset (ms)	RTT (ms)
1	0	198.51
2	100	209.71
3	200	198.47
4	300	196.92
5	400	195.50
6	500	201.34
7	600	204.39
8	700	222.88
9	800	216.43
10	900	207.98
11	1000	198.81
12	1100	198.14
13	1200	202.55
14	1300	198.06
15	1400	195.29
16	1500	192.90
17	1600	198.41
18	1700	206.88
19	1800	214.03
20	1900	209.24
21	2000	203.20
22	2100	198.34
23	2200	216.36
24	2300	203.37
25	2400	198.13
26	2500	195.70
27	2600	206.39
28	2700	201.90
29	2800	195.20
30	2900	222.16
31	3000	203.77
32	3100	196.46
33	3200	194.63
34	3300	197.92
35	3400	195.58
36	3500	209.86
37	3600	199.96
38	3700	209.76
39	3800	208.62
40	3900	209.78
41	4000	198.67
42	4100	198.34
43	4200	208.94
44	4300	205.49
45	4400	223.02
46	4500	228.54
47	4600	213.94
48	4700	204.40
49	4800	198.38
50	4900	201.75

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 London (51.50853, -0.12574). It does not disclose either facility address.

Physical Reference	Value
WGS-84 geodesic distance	9,582.1 km
Vacuum RTT floor	63.93 ms
Standard fiber RTT floor ( $n_g=1.4679$ )	93.84 ms
Low-latency fiber material floor	93.46 ms
Engineering floor (5% path allowance)	98.54 ms
Research 1.33× mapped-fiber reference	124.8 ms
Estimated unamplified path loss	2012.2 dB
Transparent optical spans / inline amplifiers	126 / 125
Published RTT inflation over fiber floor	2.18×

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 (2026-08-15T04:03:13Z) collected 50 ICMP echo samples on this route. Distribution statistics from that round:

Round Statistic	Value
Minimum RTT	192.9 ms
Average RTT	204.3 ms
Maximum RTT	228.54 ms
Standard deviation	8.36 ms
Stdev / average	4.1%

RTT trend

Estimated route stability across the selected time window.

Average: 204.5 ms
Minimum: 202.6 ms
Maximum: 206.3 ms
Average loss: 0.03%

Route Context

Departure PoP: Tokyo (TYO)
Destination PoP: London (LON)
Region overview: Asia Pacific → Europe
Full global matrix: Backbone Latency Matrix
Physical methodology: Theoretical Fiber Latency

Reverse direction

London to Tokyo latency and RTT — 203.3 ms

Fastest routes departing Tokyo (TYO)

Tokyo to Taipei latency and RTT — 32.1 ms
Tokyo to Hong Kong latency and RTT — 45.6 ms
Tokyo to Singapore latency and RTT — 69.6 ms
Tokyo to Seattle latency and RTT — 84.6 ms
Tokyo to Los Angeles latency and RTT — 101.5 ms

Fastest routes arriving at London (LON)

Amsterdam to London latency and RTT — 5.1 ms
Paris to London latency and RTT — 7.1 ms
Frankfurt to London latency and RTT — 12.6 ms
Berlin to London latency and RTT — 15.9 ms
Marseille to London latency and RTT — 24.5 ms

Same corridor (Asia Pacific → Europe)

Hong Kong to Moscow latency and RTT — 116.6 ms
Taipei to Moscow latency and RTT — 131.7 ms
Singapore to Marseille latency and RTT — 138.8 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-lon.pings.{csv,json,yaml}. When citing, include the route, the measurement round timestamp, and the dataset version — for example: "Hats Network latency dataset, Tokyo → London round 2026-08-15T04:03:13Z, CC BY 4.0".

Data auto-generated on August 15, 2026. Explore the full interactive latency matrix or browse more city-pair routes.

Tokyo, Japan → London, UK RTT