Wingspan is the distance from one wingtip to the other when a bird, airplane, or other flying creature stretches its wings out fully. When an eagle soars with its wings spread wide, its wingspan might measure seven feet or more. A tiny hummingbird might have a wingspan of only three inches, while a wandering albatross holds the record among living birds at over eleven feet.

Pilots and aircraft designers care deeply about wingspan because it affects how a plane flies. Gliders have very long wingspans to help them stay aloft without engines, catching rising air currents to soar like hawks. Fighter jets often have shorter wingspans so they can turn quickly and fit on aircraft carriers.

The word applies to anything with wings: butterflies, bats, dragonflies, even pterodactyls. When scientists discover a new species or study how animals fly, measuring the wingspan helps them understand how that creature moves through the air. A larger wingspan usually means an animal can glide more efficiently but might have trouble in tight spaces, while a smaller wingspan allows for quick, agile flight through forests or around obstacles.