Distance Between Cities

Great-circle distance, not road distance

The number here is the great-circle distance — the shortest arc across the curve of the Earth, the same path a long-haul plane roughly traces. It is the “as the crow flies” distance, always shorter than the distance you would actually drive. A road trip winds around mountains, coastlines, lakes and one-way streets, so real driving distance is typically 15–40% longer than the straight-line figure here. Use it for planning, comparisons and a sense of scale; use a routing service when you need turn-by-turn road mileage.

How to measure the distance between two places

1. Enter your starting place. Type a city, address or landmark in the “From” box (for example, “Paris, France”).
2. Enter your destination. Type the second place in the “To” box (for example, “Rome, Italy”).
3. Calculate. Press the button — each place is looked up to its exact coordinates on the WGS84 datum, then the distance and direction are computed.
4. Read the results. You get the distance in km, miles and nautical miles, the initial bearing and compass direction, the geographic midpoint, and indicative driving and flying times.
5. Refine on the map. Both places appear as pins joined by a line; drag a pin to fine-tune a point and the numbers update instantly.

How the travel-time estimates work

The driving and flying times are deliberately rough estimates based on the straight-line distance, not on real routes or schedules. The driving estimate assumes a steady average of about 80 km/h (50 mph) over the great-circle distance; it ignores traffic, stops, terrain, ferries and the fact that roads are longer than the straight line, so treat it as an order-of-magnitude guide. The flying estimate assumes a cruising speed of roughly 800 km/h (about 430 knots) over the great-circle path, with no taxi, climb, descent, holding or airport transfer time. For an exact journey time, check a routing service or an airline timetable.

Units and what each one means