Free Fall Calculator
Calculate fall time and impact velocity for an object dropped from height, or distance and speed after a fall time.
How it works
- 1Choose whether you know the drop height or the fall time.
- 2Enter your value; the unit toggle switches all dimensional fields between metric and imperial.
- 3Results are computed instantly using the kinematic equations t = √(2h ÷ g) and v = √(2gh), with g = 9.80665 m/s².
Use cases
- Physics students verifying free-fall lab measurements.
- Engineers estimating impact speed for safety and packaging design.
- Game developers tuning gravity and jump mechanics with real physics.
Frequently asked questions
What formulas does this calculator use?
For a known drop height h: fall time t = √(2h ÷ g) and impact velocity v = √(2gh), where g ≈ 9.807 m/s². For a known fall time t: distance d = ½gt² and velocity v = gt. For example, dropping an object from 20 m gives t = √(40 ÷ 9.807) ≈ 2.02 s and v = √(2 × 9.807 × 20) ≈ 19.8 m/s.
Does this account for air resistance?
No. The calculator assumes ideal free fall in a vacuum. In reality, air resistance (drag) slows the object, making actual fall times longer and impact velocities lower than shown — especially for light or large objects at high speeds.
Can I use imperial units?
Yes. Toggle the unit system to imperial at the top. Heights are entered in feet and velocities are shown in ft/s. The core always computes in SI (metres, m/s) and converts the display values for you.
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