Terminal Velocity Estimator
Terminal velocity is the speed at which gravity-driven motion reaches force balance with drag. This estimate uses a simple quadratic-drag model with constant air density and shape inputs.
How to use this calculator
- Enter mass, gravity, fluid density, drag coefficient and projected reference area.
- Check that all inputs use the same units, period and population scope.
- Change one assumption at a time when comparing scenarios.
Formula used by terminal velocity estimator calculator
vₜ = √(2mg ÷ (ρCᴅA)).
- vₜ = √(2mg ÷ (ρCᴅA)).
- Shape, orientation, wind, buoyancy and changes in drag coefficient may materially change the actual result.
- The tool validates inputs and rounds displayed figures for readability; it does not validate assumptions against external records.
Worked examples
Worked example
A 0.08 kg object with entered air density, drag coefficient and area is evaluated using the quadratic-drag balance.
The model balances m g with ½ρCᴅAv² and solves for v.
The calculator returns idealized speed in m/s and km/h.
Understanding the result
Terminal velocity is the speed at which gravity-driven motion reaches force balance with drag. This estimate uses a simple quadratic-drag model with constant air density and shape inputs.
Shape, orientation, wind, buoyancy and changes in drag coefficient may materially change the actual result.
Important notes
Shape, orientation, wind, buoyancy and changes in drag coefficient may materially change the actual result.
Treat the result as an estimate from the entered assumptions. For safety, legal, engineering, health or commercial decisions, verify relevant specifications and professional guidance.
Frequently asked questions
Why is area perpendicular to airflow?
That area is the reference area used in the quadratic drag equation.
Can I use this for human fall safety?
No. It is a simplified physics estimate and must not be used as a safety or jump-planning tool.
How should I interpret this result?
Shape, orientation, wind, buoyancy and changes in drag coefficient may materially change the actual result.
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Learn the method behind the number or compare the terminology before using the calculator.
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This page provides a calculation tool plus explanatory information so you can understand what the result means and when the underlying method may not fit your situation.