Calculator 07 · Network
How far can the sites be apart?
Set the distance, how much the fiber wanders and your latency budget. Watch light make the round trip and see how far the budget reaches.
Fiber follows roads, rails and rights-of-way, so it runs longer than the map line.
Switching, routing and amplification added to the round trip.
What the workload can tolerate. Set it from the application, not a rule of thumb.
Round trip
1.52ms
Inside your budget
One way, fiber only
0.66ms
84 fiber miles
Budget reaches
217miles
Straight-line, at this route factor
For early planning only. Results follow from the inputs and the stated assumptions; they are not engineering, financial or legal advice.
How the math works
Light in glass
Map distance to fiber distance
Round trip and budget
Questions
How much latency does fiber add per mile?
About 7.9 microseconds per fiber mile one way, or about 15.8 microseconds round trip, before switching and routing.
What is a route factor?
The ratio of the actual fiber route length to the straight-line distance between two points. Fiber rarely runs in a straight line, so the factor is above 1.
What latency budget should I use?
One set by the application: synchronous storage replication, trading systems and interactive workloads each have their own limits. This calculator does not assume one.
Why is my measured latency higher?
Real networks add queuing, routing detours, protocol overhead and congestion. Treat this as the physical floor.