Free Fall Calculator

Kaava

How this is calculated

This calculator models an object released from rest (initial velocity zero) and falling under a constant gravitational acceleration g, ignoring air resistance. You choose what you know: the drop height h (in metres) or the fall time t (in seconds). The gravitational acceleration g defaults to 9.81 m/s² for Earth, but you can change it for other bodies such as the Moon (1.62) or Mars (3.71).

When you supply the height, the fall time is t = √(2h / g) and the impact velocity is v = √(2·g·h), which equals g·t. When you supply the time instead, the distance fallen is h = ½·g·t² and the impact velocity is simply v = g·t. The curve shows the position s(τ) = ½·g·τ² across the fall, which is the parabola characteristic of constant acceleration.

Results assume a vacuum and a uniform g, so they overestimate real speeds for light or large objects where drag matters, and they are only accurate over short drops where g stays roughly constant. Inputs must be non-negative; a zero or negative gravity is rejected because it has no physical meaning here.