Kinematics
Free Fall Calculator
Calculate distance, velocity and time for objects in free fall. Works for Earth, Moon, Mars and custom gravity.
Result
Final Velocity
—
m/s
Time
—
s
Distance
—
m
Step-by-Step Solution
What is Free Fall?
Free fall is the motion of an object under the influence of gravity alone, with no other forces (like air resistance) acting on it. In free fall, every object — regardless of mass — accelerates at exactly the same rate. Near Earth's surface, this is approximately 9.81 m/s² downward.
h = ½gt² | v = gt | v² = 2gh
h = height (m) | v = velocity (m/s) | g = gravity (m/s²) | t = time (s)
Gravity on Different Planets
| Body | g (m/s²) | Relative to Earth |
|---|---|---|
| Earth | 9.81 | 1.00× |
| Moon | 1.62 | 0.165× |
| Mars | 3.72 | 0.379× |
| Jupiter | 24.79 | 2.53× |
| Sun | 274 | 27.9× |
💡 Galileo showed that all objects fall at the same rate regardless of mass. The famous Leaning Tower of Pisa experiment (1589) demonstrated that a 10 kg and 1 kg ball hit the ground simultaneously.
Frequently Asked Questions
Does mass affect free fall speed?
No. In the absence of air resistance, all objects fall at the same rate. This is because while a heavier object has more gravitational force acting on it, it also has more inertia (mass) — these effects exactly cancel out.
What is terminal velocity?
Terminal velocity is reached when air resistance equals gravitational force, so the object stops accelerating. For a skydiver it is around 55 m/s (200 km/h). This calculator assumes no air resistance (true free fall).
How far does something fall in 1 second on Earth?
h = ½ × 9.81 × 1² = 4.905 metres. After 2 seconds: 19.62 m. After 3 seconds: 44.1 m. The distance increases as the square of time.