This free fall calculator takes the figures you already have and applies the relationship behind free fall calculations for you, giving time of fall (t) and velocity (v) from gravitational acceleration (g), height (h) and initial velocity (v₀).
What Is the Free Fall Calculator?
This free fall calculator is for the kind of problem where you know the physical quantities but not the number you need. It turns gravitational acceleration (g), height (h) and initial velocity (v₀) into time of fall (t) and velocity (v).
Physics calculations go wrong in predictable ways, usually through mixing units or dropping a digit. Work through the result one step at a time and check that the figures are the size you would expect at each stage.
How the Free Fall Physics Works
The relationship is applied step by step, and each step is a standard piece of physics rather than a single opaque formula. That means you can check the intermediate values against what the theory predicts, which is usually faster than checking only the final answer.
Keep every value in the same unit system throughout the calculation. Mixing metres and feet part way through is the single most common reason a correct formula gives a wrong answer.
Units, Assumptions and the Limits of the Model
The calculation assumes ideal conditions: no air resistance, no heat loss, and dimensions that do not change while you work. Those assumptions are reasonable for most classroom and engineering estimates, and unreasonable for anything more precise.
Where a value is a rate, it has to be quoted for the same period as everything else. A per-hour figure cannot be combined with a per-day figure without converting one of them first.
A Worked Example
Working through an example, with gravitational acceleration (g) set to 10, height (h) set to 5, initial velocity (v₀) set to 2, the calculator returns time of fall (t) of 0.8198, and velocity (v) of 10.19804. Substitute your own figures and the same steps produce the same kind of answer.
Frequently Asked Questions
What do I need to work out time of fall (t)?
Enter gravitational acceleration (g), height (h) and initial velocity (v₀). The calculator then works through the relationship and reports time of fall (t) and velocity (v).
What does the free fall actually calculate?
It takes gravitational acceleration (g), height (h) and initial velocity (v₀) and converts them into time of fall (t) and velocity (v) using the standard relationship for this problem. Each step is applied in turn, so every output is traceable back to the numbers you typed in.
How should I enter gravitational acceleration (g)?
Use the value you actually have, in the unit shown next to the field. Enter every value in the same unit system. The calculator assumes the figures you supply are consistent, so it cannot correct a mistake that happens before the calculation starts.
Is the answer exact?
It is as exact as the formula and the inputs allow. The method itself is the standard one for this problem, so the only sources of error are the figures you enter and the precision you ask for.
Does anything you type get stored?
No. The whole calculation runs inside your browser, and nothing you enter is uploaded, logged or sent anywhere.