RTT measurements from Johannesburg, South Africa to Seattle, USA: average 281.2 ms, 0% packet loss, and stability context for this ICMP route.

🇿🇦 Johannesburg, South Africa (JNB) → 🇺🇸 Seattle, USA (SEA)

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

In measurement round 2026-08-16T04:07:28Z, 50 ICMP echo requests were sent from Johannesburg, South Africa to Seattle, USA at 100 ms intervals. The average round-trip time was 281.2 ms, with a minimum of 267.91 ms and a maximum of 315.6 ms, and all 50 probes were returned, so packet loss was zero percent.

The great-circle distance between the two cities is 16,502.7 km. A round trip at the vacuum speed of light would need 110.09 ms, while a theoretical direct fiber route would need at least 161.61 ms. The measured average is 1.74 times that fiber floor, a fiber efficiency of 57.5 percent, which shows meaningful routing overhead for an intercontinental route.

Across the 19 outbound routes measured in this round, this leg ranks 11th by average RTT, placing it near the midpoint of the set. Its 9.73 ms standard deviation is about 3.46 percent of the mean, close to the 3.28 percent median variability seen across the network, and jitter was 9.21 ms. The route is therefore stable and loss-free even though its absolute latency is high.

For planning purposes, the realistic ICMP RTT envelope for Johannesburg to Seattle in this round is 267.91 ms to 315.6 ms, with 281.2 ms as a reliable baseline near the center of that range.

Latency Summary

Metric	Value
RTT	281.2 ms
Jitter	9.21 ms
Packet Loss	0%
Standard Fiber Floor	161.61 ms
Fiber Efficiency	57.5%
Latency Tier	High
Source Region	Africa
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: JNB → SEA

50 ICMP echo samples at 100 ms intervals · round 2026-08-16T04:07:28Z · avg 281.2 ± 1.38 ms (SE)

Sample distribution: box = interquartile range (275.1–285.6 ms), median 278.8 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 (161.6 ms) for this route.

Full 50-sample dataset

Seq	Offset (ms)	RTT (ms)
1	0	285.87
2	100	285.59
3	200	296.67
4	300	285.59
5	400	275.69
6	500	272.33
7	600	272.41
8	700	315.60
9	800	291.18
10	900	278.40
11	1000	275.31
12	1100	275.31
13	1200	271.40
14	1300	269.00
15	1400	286.83
16	1500	283.44
17	1600	282.02
18	1700	294.84
19	1800	285.23
20	1900	275.50
21	2000	294.19
22	2100	276.10
23	2200	285.41
24	2300	274.77
25	2400	270.19
26	2500	267.91
27	2600	278.34
28	2700	273.81
29	2800	281.89
30	2900	283.78
31	3000	276.46
32	3100	280.94
33	3200	280.06
34	3300	277.95
35	3400	271.55
36	3500	289.12
37	3600	283.64
38	3700	279.27
39	3800	275.08
40	3900	272.34
41	4000	277.35
42	4100	271.61
43	4200	268.69
44	4300	286.35
45	4400	277.20
46	4500	286.46
47	4600	312.47
48	4700	283.41
49	4800	290.26
50	4900	275.19

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 Johannesburg (-26.20227, 28.04363) and Seattle (47.60621, -122.33207). It does not disclose either facility address.

Physical Reference	Value
WGS-84 geodesic distance	16,502.7 km
Vacuum RTT floor	110.09 ms
Standard fiber RTT floor ( $n_g=1.4679$ )	161.61 ms
Low-latency fiber material floor	160.96 ms
Engineering floor (5% path allowance)	169.71 ms
Research 1.33× mapped-fiber reference	214.94 ms
Estimated unamplified path loss	3465.6 dB
Transparent optical spans / inline amplifiers	217 / 216
Published RTT inflation over fiber floor	1.74×

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	267.91 ms
Average RTT	281.2 ms
Maximum RTT	315.6 ms
Standard deviation	9.73 ms
Stdev / average	3.5%

RTT trend

Estimated route stability across the selected time window.

Average: 281.4 ms
Minimum: 279.2 ms
Maximum: 283.5 ms
Average loss: 0.01%

Route Context

Departure PoP: Johannesburg (JNB)
Destination PoP: Seattle (SEA)
Region overview: Africa → North America
Full global matrix: Backbone Latency Matrix
Physical methodology: Theoretical Fiber Latency

Reverse direction

Seattle to Johannesburg latency and RTT — 282.1 ms

Fastest routes departing Johannesburg (JNB)

Johannesburg to London latency and RTT — 158 ms
Johannesburg to Amsterdam latency and RTT — 163.2 ms
Johannesburg to Paris latency and RTT — 164.4 ms
Johannesburg to Frankfurt latency and RTT — 166 ms
Johannesburg to Marseille latency and RTT — 172 ms

Fastest routes arriving at Seattle (SEA)

Los Angeles to Seattle latency and RTT — 26.9 ms
New York to Seattle latency and RTT — 58.7 ms
Ashburn to Seattle latency and RTT — 62.3 ms
Miami to Seattle latency and RTT — 81.9 ms
Tokyo to Seattle latency and RTT — 84.8 ms

Same corridor (Africa → North America)

Johannesburg to New York latency and RTT — 221.8 ms
Johannesburg to Ashburn latency and RTT — 229 ms
Johannesburg to Miami latency and RTT — 259.9 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/jnb-sea.pings.{csv,json,yaml}. When citing, include the route, the measurement round timestamp, and the dataset version — for example: "Hats Network latency dataset, Johannesburg → Seattle 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.

Johannesburg, South Africa → Seattle, USA RTT