Travel & transport
Aerodynamic drag & power
Calculate drag and steady power from a supplied drag coefficient and area.
A clear answer. Here’s how.
Uses dynamic pressure q=ρV²/2, drag=q Cd A and steady drag power=drag×V. The reference area must match the coefficient definition. Cd is supplied, not inferred from shape, Reynolds number or Mach number. Assumes a steady relative flow; rolling resistance, lift effects, acceleration and drivetrain losses are excluded.
See a worked example
Worked example
A fixed demonstration, separate from the values you enter above.
- Fluid density (kg/m³)
- 1.225
- Relative speed (m/s)
- 20
- Reference area for Cd (m²)
- 1
- Supplied drag coefficient Cd
- 0.5
Example result
- Dynamic pressure (Pa)
- 245
- Drag magnitude (N)
- 122.5
- Power to overcome drag (W)
- 2,450