Why this is only a ceiling
The model assigns all RTT to propagation. In reality, some time is spent in equipment, queues, access networks and indirect routes, so the geographic distance must be lower.
NETWORK PHYSICS CALCULATOR
Distance from Ping Estimator
Ping cannot reveal a unique geographic distance. It can only provide a generous propagation ceiling because routing, processing and queueing consume part of the measured RTT.
INTERACTIVE MODEL
Calculate the physical limit
This is an educational lower-bound model, not an address-level performance prediction.
Why traceroute does not fully solve it
Router locations can be missing or misleading, and individual hops may not expose the forward and return paths.
QUESTIONS
Common questions
Can ping locate a server?
No. The same RTT can result from many combinations of distance, routing and network delay.
Why divide RTT by two?
RTT includes the trip to the destination and back, so a symmetric lower-bound model uses half for one direction.
Formula and limitations
Maximum one-way propagation distance = RTT seconds × propagation speed ÷ 2.
Reference constants: NIST speed of light in vacuum. Fiber propagation uses a disclosed engineering approximation of 204,000 km/s; actual group velocity varies with the fiber.