Free Fall Time Calculator

Find the time for an object to fall from rest through a given height.

How the Math Works

The Free Fall Time Calculator uses the fundamental physics equation t = √(2h/g), where t represents time in seconds, h is the height of the fall in meters, and g is the acceleration due to gravity (approximately 9.8 m/s² near Earth's surface). This formula derives from the kinematic equations of motion, specifically starting from the position equation s = ut + ½at², where initial velocity (u) is zero for a dropped object, acceleration (a) is g, and displacement (s) equals height (h). Taking the square root of both sides after rearranging gives us the time of fall.

Practical Applications

To use this calculator practically, simply enter the height of the fall in meters or convert your measurement to meters from other units (such as feet or inches). For example, if dropping an object from a 20-story building approximately 60 meters high, the calculation would be t = √(2 × 60 / 9.8) = √(12.24) ≈ 3.5 seconds. This is useful for safety calculations in construction, sports equipment testing, or determining appropriate protective gear for activities involving height.

Day-to-Day Use

This calculation appears in everyday situations more than you might expect. When playing sports like basketball or volleyball, understanding fall time helps judge how long a ball will take to reach the ground after a missed shot. It's valuable for hobbyists working on drone operations, photography with elevated cameras, or simply explaining why it's dangerous to throw objects from rooftops. Even in daily life, it helps us intuitively understand why objects dropped from greater heights cause more damage—they've been accelerating longer and reach higher speeds upon impact.

Worked example

Drop 45 m → 3.03 s, hitting at 29.7 m/s.

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