Straight-Line vs Driving Distance, Explained
Two numbers, two different questions
Every pair page on this site publishes two distances, and the gap between them confuses people until the definitions are made plain. The straight-line distance is the shortest path over the curved surface of the Earth between the published coordinates of two cities — the route a crow, or roughly an aircraft, would care about. The driving distance is the length of the road path a car must actually follow between the same two places, through junctions, around terrain, across bridges and along streets that were built for many purposes besides connecting these two cities. Neither number is the true distance in the abstract; each is the true answer to a different question, and most planning mistakes come from answering a road question with a straight-line number.
Why the road is always longer
Roads bend for reasons that have nothing to do with your trip. They follow valleys and passes through high ground, they run to intermediate towns that existed before the highway did, they meet other roads at interchanges placed for a whole network rather than one journey, and they enter cities along corridors fixed a century ago. Water forces the clearest detours: a pair of cities separated by a bay, a wide river or a lake can be a few straight-line miles apart and an hour apart by road, because the road must travel to a bridge or a causeway first. Road engineers call the ratio between road distance and straight-line distance the circuity of a route, and on typical American intercity corridors it falls roughly between 1.1 and 1.4, which is why our documented estimate, used only where no measured route is published, multiplies the straight line by 1.25.
Which number should you use?
Use the straight-line figure to understand geography: how far apart two cities really are, whether a relocation puts you nearer to family, how city pairs compare with each other on an equal basis. Use the driving figure for anything involving a car: fuel budgeting, deciding whether a trip fits in a day, comparing driving with flying once airport time at both ends is honestly counted. And use the drive time — always labelled an estimate on this site — for scheduling, with a margin for stops and conditions. A useful habit is to look at all three together: the straight line tells you the scale of the journey, the road figure tells you its length in practice, and the ratio between them tells you how direct or how awkward the corridor between the two cities happens to be.
What neither number can tell you
Both figures are measured between the published Census points of the two cities, which stand for the city as a whole rather than for your street address. A trip from one edge of a large city to the far edge of another can differ from the centre-to-centre figure by tens of miles. Neither figure knows about the roadworks on your route this month, the storm on your day, or the accident an hour ahead of you. That is why this site presents its numbers as well-sourced planning figures with their methods attached, and why the final check before any real journey should always be a live conditions check on the day of travel.
Keep Exploring
Put the ideas on this page to work in the distance index, browse the New York hub or the Los Angeles hub for full tables, or read how we calculate every figure we publish. Each pair page applies the same method, labels measured routes and estimates differently, and names its sources, so the numbers you plan with are the numbers you can check.
Sources: Coordinates: U.S. Census Bureau Gazetteer files; driving data: OpenStreetMap/OSRM — retrieved October 2026.