# Drag Coefficient

Written by Jerry Ratzlaff on . Posted in Dimensionless Numbers

Drag coefficient, abbreviated as $$C_d$$, is a dimensionless number.  In fluid dynamics, it is used to quantify the amount of force or resistance an object experienced as it moves through the fluid stream.  It expresses a force in the direction of flow due and is related to the pressure and surface stress on an object.  The lower the drag coefficient, the easier the object moves throught the fluid, the higher the efficient, the more difficult it moves through the fluid.  To calculate the Drag Coefficient, use the calculator or equations below.

 $$\large{ C_d = \frac {2 \; F_d}{\rho \; v^2 \; A} }$$          Where: $$\large{ C_d }$$ = drag coefficient $$\large{ A }$$ = area $$\large{ F_d }$$ = drag force $$\large{ \rho }$$  (Greek symbol rho) = mass density $$\large{ v }$$ = velocity