Science & Engineering · Fluid Mechanics & Hydraulics
Aerodynamic Drag Force & Free-Fall Terminal Velocity Calculator: inputs, method, and how to read the result
Compute terminal velocity v_t = √(2mg / ρCdA) and dynamic drag force.
Choose inputs for the case you are checking
The defaults are illustrative. Replace them with values for your case and keep the units shown beside each field.
- Mass Kg: Falling or moving body mass in kilograms.
- Drag Coefficient Cd: Dimensionless drag coefficient (C_d).
- Cross Sectional Area M2: Frontal projected cross-sectional area in square meters.
- Fluid Density Kg M3: Air or fluid density in kg/m³ (1.225 sea-level air).
What the calculation includes
With the default values shown, Terminal Free-Fall Velocity is 57.68 m/s. The calculation follows Terminal Velocity & Drag Physics & Engineering Equation; the formula and variable definitions above show how the inputs combine.
One-input check: With the other defaults held constant, changing Mass Kg from 80 kg to 88 kg changes Terminal Free-Fall Velocity from 57.68 m/s to 60.49 m/s. This is a comparison inside the calculator's stated model, not a prediction.
Where to use caution
- Uses standard SI physical constants (g = 9.80665 m/s², c = 299,792,458 m/s, σ = 5.670374×10⁻⁸ W·m⁻²·K⁻⁴).
- Engineering reference model; apply appropriate safety factors and empirical calibration for critical hardware designs.
Scope: SI / NIST Physics & Engineering Standard Check the assumptions and limitations against your situation before relying on the estimate.
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