How far is it, really?

The shortest path between two points on a sphere is a great circle. On a flat map, that shows up as a curve toward the pole, which is why flights from Los Angeles to London pass near Greenland.

We check the current routes from both airports. If the destination is on the departure airport's list, there's a nonstop. If not, any airport that both of them fly to is a possible connection. We show the three that add the least distance.

No. They're estimates: flying time worked out from distance for each leg, plus an hour and a half for the connection. Real schedules may give you a shorter or much longer layover, so check actual flight times before you book.

We list up to four airlines that operate each leg themselves. Codeshare partners that sell seats on those flights aren't shown separately.