What Is the Free Fall Calculator?

The Free Fall Calculator helps you solve free fall physics problems instantly. Whether you need to find the height an object falls, the time it takes to reach the ground, or its final velocity at impact, this tool does the math for you.

Free fall refers to the motion of an object falling solely under the influence of gravity, with no air resistance. This calculator uses standard kinematic equations to provide accurate results for idealized free fall scenarios.

Core Physics Formulas

Height Calculations

h = ½gt² — Calculate height from time

t = √(2h/g) — Calculate time from height

Velocity Calculations

v = gt — Calculate velocity from time

v = √(2gh) — Calculate velocity from height

Multi-Planet Support: Explore how gravity differs across celestial bodies — from the Moon's gentle 1.62 m/s² to Jupiter's powerful 24.79 m/s².

How to Use the Calculator

Choose a Solve Mode

Select the tab for the variable you want to calculate: Height (h), Time (t), or Velocity (v). The input fields update automatically based on your selection.

Select a Planet

Pick a celestial body from the dropdown to set the gravitational acceleration, or choose "Custom" to enter your own g value for specialized scenarios.

Enter Known Values

Type the value you already know and select its unit. In Height and Velocity modes, you can enter either of two inputs for maximum flexibility.

View Results Instantly

The calculator displays the formula with your values, the primary result, and all three variables (h, t, v) simultaneously for complete insight.

Explore Conversions

Scroll down to see results converted into multiple units and a visual height comparison with famous landmarks for intuitive understanding.

Solve Mode Guide

Height Mode

Enter time or final velocity to find the distance fallen.

Time Mode

Enter height to find how long the fall takes.

Velocity Mode

Enter height or time to find the impact speed.

Key Features

Three Solve Modes

Switch between solving for height, time, or velocity with a single click. The input fields update automatically based on the selected mode, so you always know exactly what to enter.

Multi-Planet Support

Compare free fall across 8 celestial bodies: Earth, Moon, Mars, Venus, Jupiter, Saturn, Mercury, and the Sun. Each planet uses its actual gravitational acceleration, plus custom g value support.

Flexible Unit System

Input and view results in the units you prefer, with comprehensive support for metric and imperial measurements across all calculation types.

Live Formula Display

See the exact formula being used with your actual input values substituted in, making it easy to verify the calculation and learn the physics behind it.

Unit Conversion Table

Every result is automatically converted to all available units, displayed in an organized table grouped by height, time, and velocity for comprehensive reference.

Height Comparison

When calculating height, view visual comparisons with well-known landmarks like the Statue of Liberty, Eiffel Tower, Burj Khalifa, and Mount Everest for intuitive understanding.

Supported Units

Measurement Type	Available Units
Height	meters, feet, centimeters, kilometers, inches, yards, miles
Time	seconds, milliseconds, minutes
Velocity	m/s, km/h, mph, ft/s

Frequently Asked Questions

What is free fall?

Free fall is the motion of an object where gravity is the only force acting upon it. In this idealized model, air resistance is ignored. Real-world falls are affected by drag, but free fall calculations provide a useful baseline for physics problems, engineering estimates, and educational purposes.

What is gravitational acceleration (g)?

Gravitational acceleration is the rate at which an object speeds up as it falls. On Earth, g is approximately 9.807 m/s². This value varies significantly by celestial body:

Moon: ~1.62 m/s² (about 16% of Earth's gravity)
Mars: ~3.71 m/s² (about 38% of Earth's gravity)
Jupiter: ~24.79 m/s² (about 253% of Earth's gravity)

Does this calculator account for air resistance?

No. This calculator uses the idealized free fall equations without air resistance. For most short-distance falls and physics problems, these equations provide accurate results.

Important note: For long falls or objects with large surface areas (like parachutes or feathers), air resistance would significantly reduce the actual velocity and increase fall time.

Can I calculate free fall on other planets?

Yes. Select any of the 8 preset planets from the dropdown, or choose "Custom" to enter any gravitational acceleration value. This is useful for:

Physics assignments and homework problems
Space science research and comparative studies
Educational demonstrations of gravity differences
Theoretical scenarios with custom gravity values

What formulas does this calculator use?

The calculator uses the standard kinematic equations for uniformly accelerated motion starting from rest:

Free Fall Kinematic Equations

h = ½gt²     — distance fallen over time
t = √(2h/g)  — time to fall a given height
v = √(2gh)   — velocity after falling a given height
v = gt       — velocity after falling for a given time

Where: h = height, t = time, v = velocity, g = gravitational acceleration

Is my data saved or sent anywhere?

Privacy guaranteed: All calculations happen entirely in your browser. No data is uploaded, stored, or sent to any server. Your calculations remain completely private.