Terminal Velocity Calculator Human

An easy-to-use tool to estimate the maximum speed a person reaches during freefall.

Estimated Terminal Velocity:

195.1 km/h

54.2 m/s

Gravitational Force: 735.75 N | Air Density: 1.225 kg/m³

What is the Terminal Velocity of a Human?

Terminal velocity is the maximum, constant speed an object reaches when falling through a fluid, such as air. For a human in freefall, this occurs when the upward force of air resistance (drag) becomes equal to the downward force of gravity. At this point, the net force on the body is zero, meaning acceleration stops, and the person continues to fall at a constant speed. This concept is famously demonstrated by skydivers, who can manipulate their terminal velocity by changing their body posture. Our terminal velocity calculator human provides a precise estimation of this speed based on key physical factors.

Terminal Velocity Formula and Explanation

The calculation for terminal velocity is derived from the point where gravitational force equals the drag force. The formula used by our calculator is:

v_t = √((2 * m * g) / (ρ * A * C_d))

This equation shows how mass, gravity, air density, area, and drag coefficient all interact to determine the final speed.

Formula Variables

Variable	Meaning	Unit (Metric/Imperial)	Typical Range for a Human
vt	Terminal Velocity	m/s or ft/s	50 – 90 m/s
m	Mass of the object	kg or lb	50 – 120 kg
g	Acceleration due to gravity	9.81 m/s² or 32.2 ft/s²	Constant
ρ (rho)	Density of the fluid (air)	kg/m³ or lb/ft³	~1.225 kg/m³ at sea level
A	Projected cross-sectional area	m² or ft²	0.18 (head-first) to 0.9 (flat) m²
Cd	Drag Coefficient	Dimensionless	0.7 (streamlined) to 1.4 (loose clothing)

Practical Examples of Calculating Terminal Velocity

Example 1: Average Skydiver (Belly-to-Earth)

An 80 kg skydiver assumes a stable, belly-to-earth position, presenting a large surface area.

• Inputs: Mass = 80 kg, Area = 0.7 m², Drag Coefficient = 1.0
• Units: Metric
• Results: The calculated terminal velocity is approximately 59.7 m/s or 215 km/h. This is a typical speed for recreational skydivers.

Example 2: Competitive Skydiver (Head-Down)

A 90 kg competitive skydiver orients themselves into a head-down, streamlined position to maximize speed.

• Inputs: Mass = 198 lbs, Area = 2.2 ft², Drag Coefficient = 0.7
• Units: Imperial
• Results: The terminal velocity calculator human estimates a speed of around 278 ft/s or 190 mph (approx. 85 m/s). This demonstrates how reducing area and drag significantly increases speed.

How to Use This Terminal Velocity Calculator Human

1. Select Unit System: Choose between Metric (kg, m) and Imperial (lb, ft) units. The labels will update automatically.
2. Enter Mass: Input the person’s mass in kilograms or pounds.
3. Enter Area: Provide the estimated cross-sectional area. A belly-to-earth position is typically 0.6-0.8 m², while a head-down position is much smaller, around 0.2-0.4 m².
4. Set Drag Coefficient: Use the drag coefficient (Cd). A value of 1.0 is standard for a flat orientation, while 0.7 is for a more streamlined, head-first posture.
5. Interpret Results: The calculator instantly displays the terminal velocity in primary (km/h or mph) and secondary (m/s or ft/s) units, along with the forces involved.

Key Factors That Affect Human Terminal Velocity

• Mass: A heavier person has a greater gravitational force to overcome air resistance, resulting in a higher terminal velocity.
• Body Orientation (Area): This is the most significant factor a skydiver can control. A flat, spread-eagle position maximizes surface area, increases drag, and slows the descent. A head-down, pencil-like dive minimizes area, reduces drag, and increases speed dramatically.
• Air Density: Terminal velocity is lower at lower altitudes where the air is denser, providing more resistance. A person falling from a very high altitude will initially have a higher terminal velocity that decreases as they enter denser air.
• Drag Coefficient: This is determined by the shape and texture of the falling object. Loose, baggy clothing will flap and increase the drag coefficient, slowing a person down more than a sleek, tight-fitting jumpsuit.
• Gravity: While largely constant near the Earth’s surface, slight variations in ‘g’ with altitude technically affect the gravitational force.
• Buoyancy: While the buoyant force of air is real, its effect on a dense object like a human body is extremely small and is usually ignored in these calculations.

Frequently Asked Questions (FAQ)

1. What is the average terminal velocity for a human?

In a stable belly-to-earth position, it’s about 55 m/s (120 mph or 195 km/h). In a head-down position, it can increase to over 80 m/s (180 mph or 290 km/h).

2. How long does it take to reach terminal velocity?

It typically takes about 10-15 seconds of freefall, covering a distance of roughly 450-500 meters (about 1,500 feet).

3. Can you survive a fall at terminal velocity?

Surviving a fall at terminal velocity is extremely rare and depends entirely on the landing surface. A landing in deep water, soft snow, or a steep, vegetation-covered slope can dissipate the impact forces, but it is not something to be expected.

4. Why does a feather fall slower than a bowling ball?

The feather has a very large surface area and low mass, giving it a high amount of air resistance relative to its weight. This means its terminal velocity is very low. The bowling ball’s high mass and small area mean its weight far exceeds the air resistance for a longer time, allowing it to accelerate to a much higher speed.

5. How does this calculator handle units?

The terminal velocity calculator human automatically handles all conversions. When you select Imperial, it uses the correct Imperial value for gravity and air density and expects inputs in pounds and square feet. The final calculation is correct for the chosen system.

6. What is the drag coefficient (Cd)?

It’s a dimensionless number that quantifies how much air resistance an object generates. A low Cd means the object is very streamlined (like a bullet), while a high Cd means it creates a lot of drag (like a parachute).

7. Does altitude affect terminal velocity?

Yes. At higher altitudes, the air is less dense, which means less air resistance. This results in a higher terminal velocity. This is why high-altitude skydivers can achieve record-breaking speeds.

8. Is the area input my total skin surface area?

No, it is the ‘projected’ or ‘frontal’ cross-sectional area. This is the 2D shadow your body would cast on the ground if the sun were directly overhead.