Estimated travel durations
The straight-line distance from Sofia to Istanbul is 505 kilometers (314 miles). This is the crow-flies distance calculated using the Haversine formula.
A direct flight from Sofia to Istanbul takes approximately 2h. This is an estimate based on an average cruising speed of 800 km/h and does not include boarding, taxiing or layover time.
Driving from Sofia to Istanbul would take approximately 5h at an average speed of 85 km/h. The actual driving time may vary depending on road conditions, traffic and border crossings.
The distance from Sofia to Istanbul is 314 miles (505 km) as the crow flies.