Free Fall Calculator

Free fall describes motion controlled only by gravity. This calculator uses constant-acceleration kinematics to determine how long an object takes to travel a vertical distance and how fast it is moving at the end. Enter height or downward distance in meters, an initial downward velocity in meters per second, and gravitational acceleration in meters per second squared. On Earth near sea level, 9.81 meters per second squared is a common approximation. Other planets, moons, elevations, and precision requirements may call for a different value. The calculation first applies final velocity squared equals initial velocity squared plus two times gravity times distance. The positive square root gives the final downward speed. Fall time then equals final velocity minus initial velocity, divided by gravity. These equations assume that distance, initial velocity, and gravity all point in the same downward direction. For an object simply released from rest, enter zero initial velocity. For an object thrown downward, enter its positive launch speed. Upward launches require a signed-motion treatment beyond this calculator's intended model. Air resistance is deliberately omitted. In a vacuum, objects of all masses accelerate equally under the same gravitational field, so mass is not an input. In ordinary air, shape, area, density, and drag can limit speed, especially for light objects or long falls. A compact dense object falling a short distance may be reasonably approximated by the vacuum equations, while a leaf, parachute, or skydiver is not. The ideal result is therefore a useful physics reference and often an upper estimate of impact speed in air. Height should represent the actual vertical displacement, not the length of a sloped path. Keep every quantity in SI units unless you convert it before entry. Measurement uncertainty and local variation in gravity should guide how many digits you retain. The calculator reports mathematical values with several decimal places, but that display precision does not guarantee equal physical accuracy. For safety analysis, impact design, or long atmospheric descents, include aerodynamic drag, wind, orientation changes, material deformation, and uncertainty rather than relying only on the ideal free-fall result.