Drag count

A drag count is a dimensionless unit used by aerospace engineers.

[1][2] As the drag forces present on automotive vehicles are smaller than for aircraft, 1 drag count is commonly referred to as 0.0001 of

is defined as: where: The drag coefficient is used to compare the solutions of different geometries by means of a dimensionless number.

A drag count of 200 to 400 is typical for an airplane at cruise.

[4] A reduction of one drag count on a subsonic civil transport airplane means about 200 lb (91 kg) more in payload.