Free Fall Calculator
Calculate how long an object takes to fall and how fast it hits the ground — the simplest possible case of the SUVAT equations, with initial velocity usually zero and acceleration equal to gravity.
Free Fall Calculator Tool
Quick-load a scenario:
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Step-by-Step Solution
How This Calculator Works
Free fall is motion under gravity alone, with no air resistance and (usually) no initial velocity. It's the simplest possible SUVAT problem: initial velocity u is typically 0, acceleration a equals g, and you're solving for how long the fall takes and how fast the object is moving when it lands.
Enter a height and this calculator solves for fall time and impact velocity. If the object was already moving when it started falling — thrown downward, for example — enter that as the initial velocity. Switch to "Height (from Time)" if you know how long something fell and want to find the height instead.
Formulas Used
All four relationships are the free-fall special case of the general SUVAT equations, with a = g:
And the two most useful rearrangements when time isn't known directly:
A Few Things Worth Knowing
- Mass doesn't matter. Every object accelerates at the same rate under gravity alone — a coin and a hammer dropped together land at the same instant.
- This model ignores air resistance. It's accurate for dense, compact objects falling short distances, but not for light or wide objects like feathers, paper, or parachutes, where drag dominates.
- For sideways motion, use the Projectile Motion Calculator instead — free fall is just its 90°, no-horizontal-velocity special case.
- For the fully general version of these equations, with any three of the five kinematic variables, see the SUVAT Equations Calculator.
Related Calculators and Tools
Frequently Asked Questions
What is the free fall formula?
The two core formulas are v = gt (impact velocity from time) and h = ½gt² (distance fallen from time), both starting from rest. Combined, they give t = √(2h/g) for fall time and v = √(2gh) for impact velocity directly from height — no need to find time first.
Does mass affect how fast something falls?
No. In the absence of air resistance, every object accelerates at exactly the same rate under gravity, regardless of its mass. A bowling ball and a feather dropped together in a vacuum land at the same instant — famously demonstrated on the airless Moon during Apollo 15 in 1971.
Why does a feather fall slower than a hammer in real life?
Air resistance, not mass. A feather has a large surface area relative to its weight, so air drag slows it dramatically more than it slows a hammer. This calculator models ideal free fall with no air resistance — accurate for dense objects falling short distances, but not for light or wide objects like feathers or paper.
How is free fall different from projectile motion?
Free fall is the special case of projectile motion where the launch angle is 90° (straight down or straight up) and there is no horizontal velocity component. For any motion that also moves sideways, use the Projectile Motion Calculator, which handles both the horizontal and vertical components together.
The Scientist Behind Free Fall
The Physicist Behind This Calculator
Galileo Galilei (1564–1642)
Galileo's inclined-plane experiments were the first to show that falling bodies accelerate uniformly, regardless of mass — the exact relationship this calculator solves.
Read his full biography →