ICMP echo RTT measurement from Frankfurt, Germany to London, UK: average latency 12.9 ms, zero packet loss over 639.5 km.

🇩🇪 Frankfurt, Germany (FRA) → 🇬🇧 London, UK (LON)

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

ICMP echo RTT measurements from Frankfurt to London in round 2026-08-16T04:07:28Z averaged 12.9 ms over 50 samples, with a minimum of 12.38 ms, a maximum of 14.46 ms, and 0% packet loss.

Given a geodesic distance of 639.5 km, the vacuum floor is 4.27 ms and the fiber floor is 6.26 ms. The measured RTT is 2.06 times the fiber floor, or 48.5% fiber efficiency, showing that this cross-border route carries more overhead above the optical straight-line bound than the tightest possible path.

Within a route set of 19 measured paths, this route ranked fourth, while the network median variability was 3.28% of average RTT. Here the standard deviation was 0.43 ms and jitter was 0.33 ms, approximately 3.3% of the mean, placing stability near the network median.

Zero packet loss and ultra-low tier latency still make this a consistent reference for Frankfurt–London RTT, though the lower fiber efficiency hints at more headroom for path optimization than the raw distance alone implies.

Latency Summary

Metric	Value
RTT	12.9 ms
Jitter	0.33 ms
Packet Loss	0%
Standard Fiber Floor	6.26 ms
Fiber Efficiency	48.5%
Latency Tier	Ultra-Low
Source Region	Europe
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: FRA → LON

50 ICMP echo samples at 100 ms intervals · round 2026-08-16T04:07:28Z · avg 12.9 ± 0.06 ms (SE)

Sample distribution: box = interquartile range (12.6–13.1 ms), median 12.8 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 (6.3 ms) for this route.

Full 50-sample dataset

Seq	Offset (ms)	RTT (ms)
1	0	12.62
2	100	12.63
3	200	12.79
4	300	12.56
5	400	12.70
6	500	12.47
7	600	12.40
8	700	13.54
9	800	14.01
10	900	13.49
11	1000	12.82
12	1100	12.62
13	1200	12.88
14	1300	12.59
15	1400	12.50
16	1500	12.67
17	1600	12.79
18	1700	12.49
19	1800	12.82
20	1900	13.17
21	2000	12.67
22	2100	12.76
23	2200	12.82
24	2300	12.80
25	2400	13.28
26	2500	13.13
27	2600	13.09
28	2700	12.90
29	2800	12.72
30	2900	12.49
31	3000	13.19
32	3100	13.41
33	3200	13.07
34	3300	13.58
35	3400	12.97
36	3500	12.80
37	3600	12.55
38	3700	12.46
39	3800	12.38
40	3900	12.93
41	4000	12.54
42	4100	12.85
43	4200	14.46
44	4300	13.87
45	4400	13.16
46	4500	12.76
47	4600	12.95
48	4700	12.55
49	4800	12.81
50	4900	12.49

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 Frankfurt am Main (50.11552, 8.68417) and London (51.50853, -0.12574). It does not disclose either facility address.

Physical Reference	Value
WGS-84 geodesic distance	639.5 km
Vacuum RTT floor	4.27 ms
Standard fiber RTT floor ( $n_g=1.4679$ )	6.26 ms
Low-latency fiber material floor	6.24 ms
Engineering floor (5% path allowance)	6.58 ms
Research 1.33× mapped-fiber reference	8.33 ms
Estimated unamplified path loss	134.3 dB
Transparent optical spans / inline amplifiers	9 / 8
Published RTT inflation over fiber floor	2.06×

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	12.38 ms
Average RTT	12.9 ms
Maximum RTT	14.46 ms
Standard deviation	0.43 ms
Stdev / average	3.3%

RTT trend

Estimated route stability across the selected time window.

Average: 12.9 ms
Minimum: 12.8 ms
Maximum: 13.0 ms
Average loss: 0.02%

Route Context

Departure PoP: Frankfurt (FRA)
Destination PoP: London (LON)
Region overview: Europe → Europe
Full global matrix: Backbone Latency Matrix
Physical methodology: Theoretical Fiber Latency

Reverse direction

London to Frankfurt latency and RTT — 13.6 ms

Fastest routes departing Frankfurt (FRA)

Frankfurt to Amsterdam latency and RTT — 5.9 ms
Frankfurt to Berlin latency and RTT — 6.1 ms
Frankfurt to Paris latency and RTT — 7.6 ms
Frankfurt to Marseille latency and RTT — 16.4 ms
Frankfurt to Moscow latency and RTT — 34.7 ms

Fastest routes arriving at London (LON)

Amsterdam to London latency and RTT — 5.2 ms
Paris to London latency and RTT — 6.4 ms
Berlin to London latency and RTT — 15.2 ms
Marseille to London latency and RTT — 18.9 ms
Moscow to London latency and RTT — 42.4 ms

Same corridor (Europe → Europe)

London to Amsterdam latency and RTT — 5.2 ms
Amsterdam to Frankfurt latency and RTT — 5.9 ms
Berlin to Frankfurt latency and RTT — 6.1 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/fra-lon.pings.{csv,json,yaml}. When citing, include the route, the measurement round timestamp, and the dataset version — for example: "Hats Network latency dataset, Frankfurt → London 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.

Frankfurt, Germany → London, UK RTT