Everything in free fall moves in the same way, regardless of how heavy it is. This free fall time calculator works out how long an object takes to drop a given distance, how fast it is moving when it lands, and how far it has fallen after each individual second, which is the detail that makes the numbers feel real rather than abstract.
What Is the Free Fall Time Calculator?
Free fall is motion under gravity alone, with no air resistance. The defining feature is that every object accelerates at the same rate regardless of its mass, so a coin and a feather hit the ground together in an ideal vacuum.
This calculator applies the standard equation of accelerated motion to work out the fall time, the impact speed and the distance covered in the first second and the first two seconds. That last pair is usually the most instructive, because it shows how quickly the speed builds.
How the Free Fall Formula Works
h = v0t + ½g t ², solved for time as t = ( −v0 + √(v0² + 2gh) ) ÷ g
Setting the distance travelled equal to the height gives the quadratic in t, and the positive root is the fall time. The impact speed then follows from the simpler relationship v = v0 + gt, and the square of that speed divided by twice gravity is exactly the height dropped, which is the energy version of the same result.
The calculator also reports the distance fallen in the first second and the first two seconds. These are not proportional to time, which is the point: in two seconds an object falls four times as far as in one second, not twice as far.
Why the Distance Does Not Scale Linearly
Because the velocity keeps increasing. The first second contributes half of g in distance, the second second contributes another one and a half times g, and the third contributes two and a half times g. The odd numbers are the reason the total distance grows with the square of time.
This is also why a fall feels so much faster than people expect. After only one second of free fall the object has already moved about five metres, and by three seconds it is nearly 44 metres down.
Real Falls and Air Resistance
For dense objects the ideal model is close to reality. For a human, a sheet of paper or a coin, it is not: air resistance becomes comparable to gravity at fairly low speeds, and a falling human reaches a terminal velocity of roughly 55 metres per second.
Still, the ideal calculation is the right starting point for estimating impact speeds and for understanding why falls from height are so dangerous, where the speed at impact and the distance travelled in the last second matter most.
Frequently Asked Questions
How long does it take to fall 100 metres?
In a vacuum on Earth, a little over four and a half seconds, specifically 4.52 seconds. The impact speed is about 44.3 metres per second, which is roughly 160 kilometres per hour.
Does a heavier object fall faster?
Not in free fall. With no air resistance every object accelerates at exactly the same rate, so mass makes no difference at all. A heavier object only falls faster in practice because it has a lower drag-to-weight ratio and reaches terminal velocity more slowly.
How far does an object fall in the first second?
About 4.9 metres on Earth, because the distance is half of gravity multiplied by the square of the time. In the first two seconds it has fallen roughly 19.6 metres, and in three seconds about 44 metres.
What is the difference between free fall and projectile motion?
Free fall is motion with no horizontal component at all, straight down under gravity. Projectile motion adds a horizontal component that continues at constant speed, and the two are described by the same equations.
Does gravity change with altitude?
Very slightly, and much more noticeably on large bodies. Gravity decreases with altitude, so a fall from extreme height is marginally slower than the same fall near sea level. For most practical purposes the constant value of 9.81 metres per second squared is accurate enough.