Free Fall Calculator

Calculate the velocity, distance, and time for objects in free fall under gravity. Supports multiple planets and provides step-by-step solutions with trajectory data.

Free to useNo sign-up requiredUpdated Mar 2026

Free Fall CalculatorTry it now — free ▼

g = 9.80665 m/s²

h Distance v₀ Initial Velocity v Final Velocity t Time

ℹ Enter exactly 2 known values. Leave 2 fields blank to solve.

Gravitational Body

🌍 Earth 🌙 Moon 🔴 Mars 🟤 Jupiter 🟠 Venus ⚪ Mercury 🪐 Saturn ⚙ Custom

Quick Examples

↓ 100 m Drop ⏱ 3-Second Fall ⬇ Thrown Down 🌙 Moon Drop

h m

Distance Fallen

v₀ m/s

Initial Velocity

v m/s

Final Velocity

t s

Time

Embed Free Fall Calculator Widget

About Free Fall Calculator

The Free Fall Calculator computes the velocity, distance, and time for objects falling under the influence of gravity alone. Unlike a general kinematics calculator, this tool is specifically designed for gravitational free fall with built-in support for multiple celestial bodies including Earth, Moon, Mars, and Jupiter. Enter any two known values and the calculator solves for the remaining unknowns with detailed step-by-step solutions and a trajectory data table.

Free Fall Equations

Free fall is a special case of uniformly accelerated motion where the acceleration equals the gravitational acceleration g. The three fundamental equations are:

v = v₀ + gt

Final velocity from initial velocity, gravity, and time

h = v₀t + ½gt²

Distance fallen from initial velocity, gravity, and time

v² = v₀² + 2gh

Final velocity from initial velocity, gravity, and distance (no time)

How to Use This Calculator

Select a gravitational body: Choose the planet or celestial body where the free fall takes place. The calculator includes presets for Earth, Moon, Mars, Jupiter, Venus, Mercury, Saturn, and the Sun, or enter a custom gravity value.
Enter two known values: Input exactly two of the four variables: distance fallen (h), initial velocity (v₀), final velocity (v), or time (t). Leave the other two fields blank.
Click Calculate: The calculator automatically selects the appropriate free fall equations and solves for the unknown variables.
Review the results: Examine the solved values, step-by-step derivation with formulas, trajectory data table, and real-world comparisons for speed and height.

Understanding the Variables

Variable	Symbol	SI Unit	Description
Distance Fallen	h	m	Vertical distance the object has fallen (always positive)
Initial Velocity	v₀	m/s	Speed at the start of the fall (0 for objects dropped from rest)
Final Velocity	v	m/s	Speed at the end of the fall (impact velocity)
Time	t	s	Duration of the free fall
Gravity	g	m/s²	Gravitational acceleration (preset or custom)

Gravitational Acceleration by Planet

Body	g (m/s²)	Relative to Earth	Fall from 10 m (time)
🌍 Earth	9.807	1.00×	1.43 s
🌙 Moon	1.625	0.17×	3.51 s
🔴 Mars	3.721	0.38×	2.32 s
🟠 Venus	8.870	0.90×	1.50 s
⚪ Mercury	3.700	0.38×	2.32 s
🟤 Jupiter	24.79	2.53×	0.90 s
🪐 Saturn	10.44	1.06×	1.38 s
☀️ Sun	274.0	27.9×	0.27 s

Common Applications

Physics Education

Free fall is one of the first topics in introductory physics courses. Students use these equations to solve problems involving dropped objects, measuring the height of buildings by timing a falling object, and understanding the concept of gravitational acceleration.

Engineering & Safety

Engineers use free fall calculations to design safety systems such as airbags, fall arrest harnesses, and crash-test scenarios. Understanding impact velocity at different heights is critical for determining the forces involved in a fall.

Space Exploration

Astronauts and space engineers must account for different gravitational accelerations on other planets and moons. Landing procedures on Mars, for example, must account for gravity being roughly 38% of Earth's.

Sports & Recreation

Free fall physics applies to activities like skydiving (before terminal velocity), bungee jumping, cliff diving, and ski jumping. Understanding fall times and velocities helps ensure safety and improve performance.

Frequently Asked Questions

What is free fall in physics?

Free fall is the motion of an object where gravity is the only force acting upon it. In free fall, all objects accelerate downward at the same rate regardless of their mass (ignoring air resistance). On Earth, this acceleration is approximately 9.81 m/s².

What is the acceleration due to gravity on Earth?

The standard acceleration due to gravity on Earth is 9.80665 m/s² (often rounded to 9.81 or 9.8 m/s²). This value varies slightly depending on altitude and latitude, ranging from about 9.78 m/s² at the equator to 9.83 m/s² at the poles.

Does the mass of an object affect its free fall speed?

No. In a vacuum (true free fall without air resistance), all objects fall at the same rate regardless of mass. This was famously demonstrated by Galileo and later confirmed on the Moon by Apollo 15 astronaut David Scott, who dropped a hammer and feather simultaneously.

How fast does an object fall after a certain time?

The velocity of a falling object (starting from rest) after time t is v = gt, where g is gravitational acceleration. On Earth, after 1 second an object reaches about 9.8 m/s (35 km/h), after 2 seconds about 19.6 m/s (71 km/h), and after 5 seconds about 49 m/s (176 km/h).

How is free fall different on the Moon compared to Earth?

The Moon has about one-sixth the gravitational acceleration of Earth (1.625 m/s² vs 9.81 m/s²). This means objects fall about 6 times slower on the Moon. An object dropped from 10 meters would take about 1.43 seconds on Earth but about 3.51 seconds on the Moon.

Additional Resources

Reference this content, page, or tool as:

"Free Fall Calculator" at https://MiniWebtool.com/free-fall-calculator/ from MiniWebtool, https://MiniWebtool.com/

by miniwebtool team. Updated: Mar 15, 2026