Physics

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Free Fall Calculator.

Calculate ideal free-fall impact speed and time under constant gravity.

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Set your values

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02 / ANSWER

Drop height

Initial downward velocity

Gravitational acceleration

Impact velocity

0.000000

Fall time

0.000000

Educational SI model using the assumptions stated above; verify engineering and safety decisions independently.

Use Cases

Physics homework and experiments

Quickly compute theoretical impact speed and fall time for objects dropped from a known height, useful for verifying lab results or solving textbook problems.

Example: Drop a ball from 10 m with zero initial velocity on Earth (g=9.81 m/s²) to find impact speed ≈14 m/s.

Engineering and safety planning

Estimate the speed of a falling object to assess potential impact forces in design scenarios, such as drop tests or protective equipment.

Example: Calculate impact speed for a tool dropped from 5 m with an initial downward velocity of 2 m/s.

Frequently Asked Questions

How does the free fall calculator determine impact speed?: It uses the kinematic equation v = sqrt(v0² + 2*g*h), where v0 is initial downward velocity, g is gravitational acceleration, and h is drop height. This gives the speed just before impact, assuming no air resistance.
What is the time of fall in free fall?: The time is calculated from t = (v - v0) / g, where v is the impact speed, v0 is initial velocity, and g is gravitational acceleration. It represents the duration of the fall under constant gravity.
Does this calculator account for air resistance?: No, it assumes ideal free fall with constant gravitational acceleration and no air resistance. Real-world falls may have lower impact speeds due to drag.

Tips & Common Mistakes

Tips

Ensure the drop height is measured from the release point to the impact surface, in meters.
If the object is thrown downward, enter a positive initial velocity; if dropped from rest, set it to 0.
Use the standard gravitational acceleration (9.81 m/s² on Earth) unless you are on another celestial body.
Remember that this calculator ignores air resistance, so real-world speeds may be lower.

Common Mistakes to Avoid

Forgetting to convert units to meters and meters per second before entering values.
Entering initial velocity as negative when the object is thrown downward; it should be positive.
Assuming the calculated time includes the time after impact; it only covers the fall duration.

Last updated: August 13, 2026

Use Cases

Physics homework and experiments

Quickly compute theoretical impact speed and fall time for objects dropped from a known height, useful for verifying lab results or solving textbook problems.

Example: Drop a ball from 10 m with zero initial velocity on Earth (g=9.81 m/s²) to find impact speed ≈14 m/s.

Engineering and safety planning

Estimate the speed of a falling object to assess potential impact forces in design scenarios, such as drop tests or protective equipment.

Example: Calculate impact speed for a tool dropped from 5 m with an initial downward velocity of 2 m/s.

Frequently Asked Questions

How does the free fall calculator determine impact speed?

It uses the kinematic equation v = sqrt(v0² + 2*g*h), where v0 is initial downward velocity, g is gravitational acceleration, and h is drop height. This gives the speed just before impact, assuming no air resistance.

What is the time of fall in free fall?

The time is calculated from t = (v - v0) / g, where v is the impact speed, v0 is initial velocity, and g is gravitational acceleration. It represents the duration of the fall under constant gravity.

Does this calculator account for air resistance?

No, it assumes ideal free fall with constant gravitational acceleration and no air resistance. Real-world falls may have lower impact speeds due to drag.

Tips & Common Mistakes

Tips

Ensure the drop height is measured from the release point to the impact surface, in meters.
If the object is thrown downward, enter a positive initial velocity; if dropped from rest, set it to 0.
Use the standard gravitational acceleration (9.81 m/s² on Earth) unless you are on another celestial body.
Remember that this calculator ignores air resistance, so real-world speeds may be lower.

Common Mistakes to Avoid

Forgetting to convert units to meters and meters per second before entering values.
Entering initial velocity as negative when the object is thrown downward; it should be positive.
Assuming the calculated time includes the time after impact; it only covers the fall duration.

Use Cases

Physics homework and experiments

Quickly compute theoretical impact speed and fall time for objects dropped from a known height, useful for verifying lab results or solving textbook problems.

Example: Drop a ball from 10 m with zero initial velocity on Earth (g=9.81 m/s²) to find impact speed ≈14 m/s.

Engineering and safety planning

Estimate the speed of a falling object to assess potential impact forces in design scenarios, such as drop tests or protective equipment.

Example: Calculate impact speed for a tool dropped from 5 m with an initial downward velocity of 2 m/s.

Frequently Asked Questions

How does the free fall calculator determine impact speed?

What is the time of fall in free fall?

The time is calculated from t = (v - v0) / g, where v is the impact speed, v0 is initial velocity, and g is gravitational acceleration. It represents the duration of the fall under constant gravity.

Does this calculator account for air resistance?

No, it assumes ideal free fall with constant gravitational acceleration and no air resistance. Real-world falls may have lower impact speeds due to drag.

Tips & Common Mistakes

Tips

Ensure the drop height is measured from the release point to the impact surface, in meters.
If the object is thrown downward, enter a positive initial velocity; if dropped from rest, set it to 0.
Use the standard gravitational acceleration (9.81 m/s² on Earth) unless you are on another celestial body.
Remember that this calculator ignores air resistance, so real-world speeds may be lower.

Common Mistakes to Avoid

Forgetting to convert units to meters and meters per second before entering values.
Entering initial velocity as negative when the object is thrown downward; it should be positive.
Assuming the calculated time includes the time after impact; it only covers the fall duration.