Work out region latency estimate instantly with clear inputs, formula shown and shareable results.
Light in fibre travels about 200,000 km per second, and real routes are typically 1.3 to 2 times the great-circle distance, so an 8,000 km separation gives roughly 120 ms round trip before any processing. Connection setup multiplies that: TLS 1.3 adds one round trip and TLS 1.2 two, so time to first byte on a cold connection is several times the RTT.
Region latency
fibre path = distance x inefficiency; one way = path / 200000 x 1000 ms; RTT = 2 x one way + processing; first byte = RTT x (1 + handshake round trips)
Not the propagation component — it is physics. Only moving compute closer to users helps, which is what edge deployment and regional replicas exist to do.
Enormously for repeat requests. Keep-alive removes the handshake round trips entirely, cutting time to first byte to a single RTT.