Seattle to Sydney Latency, Ping & RTT | AS203314
Seattle to Sydney ping and RTT: 162.7 ms, 1.47 ms jitter, 121.96 ms fiber floor, and 75% efficiency across AS203314. Updated 2026-07-19.
🇺🇸 This page compares the published ping and round-trip time (RTT) from Seattle (SEA) to 🇦🇺 Sydney (SYD) with vacuum and optical-fiber physical limits.
Latency Summary
| Metric | Value |
|---|---|
| RTT | 162.7 ms |
| Jitter | 1.47 ms |
| Packet Loss | 0.15% |
| Standard Fiber Floor | 121.96 ms |
| Fiber Efficiency | 75% |
| Latency Tier | Fair |
| Source Region | North America |
| Destination Region | Asia Pacific |
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 () | 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 | 1.33× |
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 following estimated indicators summarize route stability for the current publication period and are intended for comparative planning rather than SLA evaluation.
| Stability Indicator | Value |
|---|---|
| Minimum RTT | 160.8 ms |
| Median RTT (p50) | 162.5 ms |
| 95th percentile RTT (p95) | 164.7 ms |
| Maximum RTT | 166.1 ms |
| Jitter | 1.47 ms |
| Packet loss | 0.15% |
RTT trend
Estimated route stability across the selected time window.
- Average
- 162.7 ms
- Minimum
- 161.0 ms
- Maximum
- 163.9 ms
- Average loss
- 0.02%
Route Context
- Departure PoP: Seattle (SEA)
- Destination PoP: Sydney (SYD)
- Region overview: North America → Asia Pacific
- Full global matrix: Backbone Latency Matrix
- Physical methodology: Theoretical Fiber Latency
Related City-Pair Routes
- Reverse direction: Sydney to Seattle latency and RTT — 161.4 ms
- Seattle to Los Angeles latency and RTT — 27.1 ms
- Seattle to New York latency and RTT — 59.1 ms
- Seattle to Ashburn latency and RTT — 61.8 ms
- Seattle to Miami latency and RTT — 81.1 ms
- Seattle to Tokyo latency and RTT — 84 ms
About This Measurement
Published RTT reflects best-case backbone path behavior. End-user latency also depends on local access networks, congestion, routing policy, and traffic engineering. Stability indicators are comparative estimates, and none of these values is an SLA.
Data auto-generated on July 19, 2026. Explore the full interactive latency matrix or browse more city-pair routes.