Term

drag coefficient

Daniel MarkFounder & Editor, Aviatopia
Published Mar 1, 2026Updated Mar 1, 20261 min read

A dimensionless number (CD) quantifying the total aerodynamic drag on a body, used in the drag equation.

aviation-glossary

Quick Facts

Type
Aerodynamic Metric
Definition
A dimensionless number (CD) quantifying the total aerodynamic drag on a body,...
Used By
Engineers, Pilots

Definition#

Drag coefficient (CD) is a dimensionless coefficient that quantifies the aerodynamic resistance of a body moving through air. It includes both parasite drag (form, skin friction, interference) and induced drag (a byproduct of lift).

Why It Matters Operationally#

Lower CD means less fuel consumption at a given speed. Aircraft designers optimize shapes and surfaces to minimize CD while maintaining adequate CL.