Free Fall Calculator
Calculate free fall instantly in your browser — the published formula, worked locally with no data sent anywhere.
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What this tool does
Calculate free fall instantly in your browser — the published formula, worked locally with no data sent anywhere. Dropped from rest in a vacuum. Air resistance is ignored — for light or large objects (paper, feathers, a person with a parachute) real fall times are much longer because of terminal velocity.
How to use the Free Fall Calculator
- Enter or select drop height in ft.
- Read the calculated result; change any measurement to compare alternatives.
Formula
From rest under gravity: time t = √(2h/g) and impact velocity v = √(2·g·h), computed with g = 32.174 ft/s² for the foot-based inputs.
- height
- Drop height (ft, before metric conversion)
Dropped from rest in a vacuum. Air resistance is ignored — for light or large objects (paper, feathers, a person with a parachute) real fall times are much longer because of terminal velocity.
Worked example
For free fall calculator, the following measurements illustrate the exact method: Drop height: 100.
Inputs
- Drop height100 ft
Result
- Fall time (s)2.49
- Impact velocity (ft/s)80.22
- Impact velocity (mph)54.69
- Impact velocity (m/s)24.45
- Height (m)30.48
Results explained
- Fall time (s)
- Fall time (s) from the formula above. Dropped from rest in a vacuum. Air resistance is ignored — for light or large objects (paper, feathers, a person with a parachute) real fall times are much longer because of terminal velocity.
- Impact velocity (ft/s)
- Impact velocity (ft/s) from the formula above. Dropped from rest in a vacuum. Air resistance is ignored — for light or large objects (paper, feathers, a person with a parachute) real fall times are much longer because of terminal velocity.
- Impact velocity (mph)
- Impact velocity (mph) from the formula above. Dropped from rest in a vacuum. Air resistance is ignored — for light or large objects (paper, feathers, a person with a parachute) real fall times are much longer because of terminal velocity.
- Impact velocity (m/s)
- Impact velocity (m/s) from the formula above. Dropped from rest in a vacuum. Air resistance is ignored — for light or large objects (paper, feathers, a person with a parachute) real fall times are much longer because of terminal velocity.
- Height (m)
- Height (m) from the formula above. Dropped from rest in a vacuum. Air resistance is ignored — for light or large objects (paper, feathers, a person with a parachute) real fall times are much longer because of terminal velocity.
Frequently asked questions
From rest under gravity: time t = √(2h/g) and impact velocity v = √(2·g·h), computed with g = 32.174 ft/s² for the foot-based inputs.
Dropped from rest in a vacuum. Air resistance is ignored — for light or large objects (paper, feathers, a person with a parachute) real fall times are much longer because of terminal velocity.
Every field is labelled with its unit — enter values in exactly the labelled unit and read the result in the labelled output unit. Fields with a unit symbol also support the site-wide imperial/metric switch, which converts before the formula runs.
It uses double-precision arithmetic and the published constants and formulas named on this page. The last displayed digit may be rounded, and real conditions can differ from the idealized model described in the assumptions.
Yes. Every calculation runs entirely in your browser; nothing you enter is uploaded, stored or shared.