Free Fall Calculator

Free fall is motion under gravity alone, ignoring air resistance. When an object drops without initial velocity, the fall time and impact speed can be found from the height alone.

Enter only the drop height (m) to get the time to reach the ground and the speed at that moment.

For example, an object in free fall from a height of 20 m reaches the ground in about 2.02 s at a speed of about 19.8 m/s.

Free Fall Calculator Calculation Method

h: height (m), g: gravity (9.8 m/s²), t: fall time (s), v: impact speed (m/s)

Fall time: 0 Second

Impact speed: 0 m/s

About This Calculator

Free fall is motion under the influence of gravity alone, ignoring air resistance. Every object — regardless of mass — falls with the same acceleration, about 9.8 m/s² near the Earth's surface.

Enter the drop height to find the fall time and the impact speed, or run it in reverse to find the height from a measured fall time.

Ignoring air resistance every object falls with the same 9.81 m/s² acceleration, so a feather and a hammer behave identically in a vacuum. Falling for three seconds covers 44.1 m and reaches 29.4 m/s. Air resistance becomes significant above about 20 m/s for a person, and terminal velocity spread-eagled is roughly 55 m/s.

Key Formula:t = √(2h / g) · v = √(2gh)

Frequently Asked Questions

Do heavier objects really fall at the same rate?

In a vacuum, yes — Apollo 15 commander David Scott demonstrated this on the Moon by dropping a hammer and a feather together. On Earth, air resistance makes light, high-drag objects such as feathers fall more slowly.

How far do you fall in 3 seconds?

Using h = ½gt² with g = 9.8 m/s², a 3-second fall covers about 44 metres and reaches roughly 29 m/s (about 106 km/h) just before impact.

Why do heavier objects seem to fall faster in daily life?

Air resistance affects large, light objects disproportionately. A stone has a much higher weight-to-drag ratio than a leaf, so the leaf slows far more. In a vacuum the two land together.

Does the mass of the Earth matter?

In principle yes: the acceleration is G times the Earth mass divided by the radius squared, and Newton third law means the Earth accelerates towards the object too. Its enormous mass makes that motion negligible.

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Sources & last update

2026-10-19