What Is a Free Fall Calculator?
A free fall calculator solves for the motion of an object falling under gravity alone, ignoring air resistance. It finds the velocity, time, and distance of a falling object using the equations of motion with gravitational acceleration. This is a core physics topic. Enter what you know — drop height or fall time — and the calculator returns the other values.
How to Use the Calculator
- Enter a known value — height, time, or initial velocity.
- Confirm gravity (9.81 m/s² on Earth by default).
- Calculate — see the velocity, time, and distance.
Free Fall Equations
For an object dropped from rest (ignoring air resistance):
| Quantity | Formula |
|---|---|
| Velocity | v = g × t |
| Distance fallen | d = ½ × g × t² |
| Time to fall | t = √(2d ÷ g) |
where g ≈ 9.81 m/s² on Earth, t is time, and d is distance.
Worked Example
An object dropped from 20 meters: time to fall = √(2 × 20 ÷ 9.81) ≈ 2.02 seconds, and the impact velocity = 9.81 × 2.02 ≈ 19.8 m/s. The distance and velocity grow because gravity accelerates the object continuously.
Key Facts About Free Fall
- Same acceleration: ignoring air resistance, all objects fall at the same rate regardless of mass.
- Velocity grows linearly with time, while distance grows with the square of time.
- Air resistance: in reality, drag eventually limits speed (terminal velocity).
Frequently Asked Questions
How do you calculate free fall velocity?
Multiply gravitational acceleration by the fall time: v = g × t. After 3 seconds, an object reaches about 9.81 × 3 ≈ 29.4 m/s.
How do you find the time to fall?
Use t = √(2d ÷ g), where d is the drop height and g is 9.81 m/s². A 20-meter drop takes about 2 seconds.
Do heavier objects fall faster?
No — ignoring air resistance, all objects fall at the same rate because gravity gives them the same acceleration regardless of mass.
What is terminal velocity?
Terminal velocity is the maximum speed a falling object reaches when air resistance balances gravity. The basic free fall equations ignore air resistance.
Is this free fall calculator free?
Yes — it is completely free, requires no signup, and solves for velocity, time, and distance.