Terminal Velocity

v = √(2mg/(ρ C_d A)) at steady drag = weight.

Inputs

Mass (kg)

C_d

Area (m²)

ρ air (kg/m³)

Tab to move between fields

Results

m/s

44.551

mph99.7

How to Use This Calculator

Enter the object mass (kg).
Set the drag coefficient Cd -- sphere ~0.47, skydiver flat ~1.0, skydiver streamlined ~0.7.
Enter the cross-sectional area (m2) and air density (kg/m3) -- 1.225 at sea level.
Review terminal velocity in m/s and mph.
Reduce area or Cd to increase terminal velocity -- relevant for vehicle aerodynamics and projectile ballistics.

How the result changes with C_d

C_d	m/s
0.51	65.493
1.76	35.221
3.25	25.919
4.5	22.027

What each input means

Mass (kg): Mass of the falling object in kilograms. Average adult is about 75 kg.
C_d: Drag coefficient. A skydiver spread-eagle is about 1.0-1.3; head-down dive is about 0.4.
Area (m²): Frontal area.
ρ air (kg/m³): Sea level ~1.225.

How this is calculated

Formula

v_t = √(2mg / (ρ × C_d × A))

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