aspect ratio

WordReference Random House Unabridged Dictionary of American English © 2026

as′pect ra′tio, 

1. Aeronautics the ratio of the span of an airfoil to its mean chord.
2. Radio and Television [Television.] the ratio of the width of an image to its height, usually the ratio 4 to 3.
3. Nautical, Naval Terms [Naval Archit.] the ratio of the height of a rudder to its fore-and-aft length.
4. [Rocketry.]
   • Rocketry Also called fineness ratio, slenderness ratio. the ratio of the mean diameter of the body of a rocket or missile to its length.
   • Rocketry the ratio of the length of the combustion chamber of a rocket motor to its diameter.
• 1905–10

Collins Concise English Dictionary © HarperCollins Publishers::

aspect ratio noun

1. the ratio of width to height of the picture on a television or cinema screen
2. the ratio of the span of a wing to its mean chord