A drag count is a dimensionless unit used by aerospace engineers. 1 drag count is equal to a of 0.0001.
As the drag forces present on automotive vehicles are smaller than for aircraft, 1 drag count is commonly referred to as 0.0001 of .
A drag count 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 is more user-friendly than the drag coefficient, as the latter is usually much less than 1. A drag count of 200 to 400 is typical for an airplane at cruise. A reduction of one drag count on a subsonic civil transport airplane means about more in payload.