Performance
Latency Calculator
Estimate network latency based on physical distance and transmission medium. Calculate round-trip time for fiber, copper, satellite, and microwave links.
Distance
Transmission Medium
Additional Delays (Optional)
Server/application processing time per endpoint
Typical router hop adds 0.2-1ms depending on load and hardware
Latency Thresholds
| RTT | Quality | Suitable For |
|---|---|---|
| <20ms | Excellent | Competitive gaming, HFT |
| 20-50ms | Very Good | Online gaming, VoIP |
| 50-100ms | Good | Video calls, streaming |
| 100-300ms | Moderate | Web browsing, email |
| >300ms | Poor | Noticeable delay |
How to Use
- 1Enter the physical distance between two points (or use quick presets)
- 2Select the transmission medium (fiber, copper, satellite, etc.)
- 3Optionally add processing delays and network hop counts
- 4View the calculated one-way latency and round-trip time
The Physics of Latency
- Speed of light: ~299,792 km/s in vacuum. This is the absolute physical limit.
- Fiber optic: Light travels at ~67% of c due to the refractive index of glass.
- Copper cable: Electrical signals travel at ~64% of c.
- GEO satellites: ~35,786 km altitude means ~240ms one-way minimum.
Real vs Theoretical
This shows the theoretical minimum. Real-world latency includes:
- Router/switch processing at each hop
- Queuing delays during congestion
- Non-direct cable routing
- Protocol overhead (TCP handshakes)
Common Routes & Latencies
| Route | Distance | Theoretical RTT | Typical RTT | Notes |
|---|---|---|---|---|
| NYC → London | 5,570 km | ~56 ms | 65-80 ms | Transatlantic subsea cables |
| NYC → Los Angeles | 3,940 km | ~40 ms | 55-70 ms | Cross-continental fiber |
| NYC → Tokyo | 10,850 km | ~108 ms | 140-180 ms | Pacific subsea cables |
| London → Sydney | 16,990 km | ~170 ms | 250-300 ms | Multiple hops required |
| GEO Satellite | 35,786 km × 2 | ~480 ms | 500-700 ms | Geostationary orbit |
| LEO Satellite (Starlink) | 550 km × 2 | ~8 ms | 20-40 ms | Low Earth orbit |
Theoretical RTT assumes fiber at 67% speed of light. Typical RTT includes real-world routing, processing, and cable path inefficiencies.
Speed of Light in Different Media
Vacuum / Air
299,792 km/s
100% of c (speed of light)
Fiber Optic
~200,000 km/s
~67% of c (refractive index ~1.5)
Copper Cable
~192,000 km/s
~64% of c (velocity factor)