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Free Fall Calculator

Fall time, impact speed and energy for an object dropped from a height (ignoring air resistance).

Enter values

Results update as you type.

Result

Fall time

2.02 s

Impact speed
19.806 m/s
Impact speed (km/h)
71.3
Drop height
20 m
Impact energy
196.13 J

Ignores air resistance — real falling objects reach a terminal velocity.

About the Free Fall Calculator

Fall time, impact speed and energy for an object dropped from a height (ignoring air resistance).

Also known as: falling object calculator, drop height calculator, impact velocity, terminal speed.

How to use this calculator

  1. Enter i know the, mass (optional), gravity and the other fields.
  2. The result updates instantly as you type — press Calculate (or Enter) at any time.
  3. Review the breakdown shown under the main result.
  4. Use Copy result or Share to save the answer or send a link with your inputs.

Formula

h = ½gt² · v = gt = √(2gh)

Worked example

Using the values pre-filled in the calculator above:

  • I know the: Height
  • Height = 20 m
  • Mass (optional) = 1 kg
  • Gravity = 9.8067 m/s²

the calculator returns:

  • Fall time: 2.02 s
  • Impact speed: 19.806 m/s
  • Impact speed (km/h): 71.3
  • Drop height: 20 m