Drag Equation Calculator

Calculate aerodynamic drag for objects moving through a fluid.

How to Use This Calculator

  1. Enter fluid density (air ≈ 1.225 kg/m³ at sea level).
  2. Provide velocity, drag coefficient, and reference area.
  3. Click Calculate to get Fd in Newtons.

Formula

Fd = ½ ρ v² Cd A

Cd depends on shape and Reynolds number; A is frontal or reference area per convention.

Frequently Asked Questions

What is a typical Cd?

Sphere ~0.47, streamlined car ~0.25–0.35, flat plate normal to flow ~1.28.

Does density vary?

Yes, with altitude and temperature. Use appropriate ρ for your conditions.