Free Fall Calculator
Use our free fall calculator to calculate time of fall and final velocity from gravitational acceleration (g), initial velocity (v₀), and height (h). Includes what free fall is in physics, the free fall time formula, and a free fall calculation walkthrough with examples.
What Is Free Fall?
In physics, free fall means motion under the influence of gravity alone (ignoring air resistance). That includes objects dropped from rest and objects thrown upward or downward, as long as gravity is the only force acting.
Free fall calculations typically use constant-acceleration kinematics with acceleration equal to g (gravitational acceleration).
This free fall calculator uses g, initial velocity (v₀), and height (h) to compute the time of fall (t) and the velocity at impact (v).
Free Fall Formulas
Free fall with constant acceleration uses standard kinematics equations. If we take downward as the positive direction and h as the vertical distance traveled, the relationships below apply.
Solve this quadratic for t (time of fall).
Once you have t, compute the final velocity.
Useful to compute v directly (choose the physically correct sign for direction).
Common shortcut when an object is simply dropped.
Then v = g·t ≈ 9.81·2.02 ≈ 19.8 m/s (downward).
How to Calculate Free Fall
- 1
Enter gravitational acceleration g (use 9.81 m/s² on Earth unless you have a different value).
- 2
Enter initial velocity v₀ (use 0 if dropped from rest; use a positive/negative value based on your direction convention).
- 3
Enter height h (vertical distance traveled).
- 4
The calculator solves h = v₀t + ½gt² for time of fall t (choosing the physically meaningful, non-negative time).
Frequently Asked Questions
Free fall is motion where gravity is the only force acting on an object (air resistance neglected). The acceleration is constant and equal to g.
Use kinematics with constant acceleration: h = v₀t + ½gt² and v = v₀ + gt. If v₀ = 0, a common shortcut is t = √(2h/g).
For an object dropped from rest (v₀ = 0), t = √(2h/g). For nonzero v₀, solve h = v₀t + ½gt² for t.
No. Standard free fall assumes no air resistance. Real objects may fall slower due to drag, especially at high speeds or with large surface area.
The quadratic equation can produce two roots, but only the non-negative time that matches the physical situation is meaningful.
Yes. If the object is thrown upward, v₀ can be in the opposite direction to gravity. The equations still work—you just need a consistent sign convention.