Calculating your terminal velocity is straightforward once you know the Terminal Velocity formula and what each input means. This guide explains the method in plain language, walks through a manual calculation, and gives worked examples you can follow — then you can do it instantly with the Terminal Velocity Calculator.
What is Terminal Velocity?
The Terminal Velocity calculation tells you your terminal velocity from a few simple inputs. The figure you are solving for here is the terminal velocity.
The Terminal Velocity formula
The core formula is:
Terminal velocity = √(2 × Mass × Gravity ÷ (Air density × Cross-section area × Drag coefficient))Here is what each input means:
- Mass — a value measured in kg. Example: 80 kg.
- Gravity — a value measured in m/s². Example: 9.81 m/s².
- Air density — a value measured in kg/m³. Example: 1.225 kg/m³.
- Cross-section area — a value measured in m². Example: 0.7 m².
- Drag coefficient — a number. Example: 1.
How to calculate it step by step
- Write down the mass (for example, 80 kg).
- Write down the gravity (for example, 9.81 m/s²).
- Write down the air density (for example, 1.225 kg/m³).
- Write down the cross-section area (for example, 0.7 m²).
- Write down the drag coefficient (for example, 1).
- Apply the formula above to get your terminal velocity.
- Double-check the result with the Terminal Velocity Calculator.
Worked examples
Example 1
| Input / Output | Value |
|---|---|
| Mass | 80 kg |
| Gravity | 9.81 m/s² |
| Air density | 1.225 kg/m³ |
| Cross-section area | 0.7 m² |
| Drag coefficient | 1 |
| Terminal velocity | 42.7836 |
With mass of 80 kg, gravity of 9.81 m/s², air density of 1.225 kg/m³ and cross-section area of 0.7 m², the terminal velocity works out to 42.7836.
Example 2
With mass of 160 kg, gravity of 9.81 m/s², air density of 1.225 kg/m³ and cross-section area of 0.7 m², the terminal velocity works out to 60.5052.
| Result | Value |
|---|---|
| Terminal velocity | 60.5052 |
Example 3
With mass of 40 kg, gravity of 9.81 m/s², air density of 1.225 kg/m³ and cross-section area of 0.7 m², the terminal velocity works out to 30.2526.
| Result | Value |
|---|---|
| Terminal velocity | 30.2526 |
Tips for an accurate result
- Keep your units consistent — mixing, say, months with years or grams with kilograms is the most common source of error.
- Round only at the very end. Rounding inputs early can shift the final answer noticeably.
- Re-run the numbers whenever an input changes, rather than estimating from an old result.
Prefer not to do the maths by hand? — the Terminal Velocity Calculator does it instantly, for free, with the formula and a worked example built in.
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