What value of g does this calculator use?

It uses the standard gravitational acceleration of 9.81 m/s² (or 32.174 ft/s² in imperial mode). This is the internationally accepted standard for Earth's surface at sea level.

Does this account for air resistance?

No. This calculator assumes ideal free fall in a vacuum — no air resistance or drag. Real-world falls at high speeds or with light objects will differ due to aerodynamic drag.

Can I calculate from a known fall time instead of height?

Yes. Switch to "From Time" mode, enter the duration in seconds, and the calculator will return the final velocity and total distance fallen.

What are the formulas used?

Time from height: t = √(2h/g). Velocity from height: v = √(2gh). Distance from time: h = ½gt². Velocity from time: v = g×t. Distance from velocity: h = v²/(2g). Time from velocity: t = v/g.

What is the maximum free-fall speed on Earth?

In a vacuum there is no limit — velocity grows linearly with time. In practice, a human body reaches terminal velocity around 53–56 m/s (120–125 mph) due to air resistance.

Free Fall Calculator

Name: Free Fall Calculator
Availability: InStock
Author: Nham Vu

Enter a height (or time) to instantly calculate free-fall duration, final velocity, and distance fallen under gravity.

Solve from

Unit system

Height (m)

Gravitational acceleration: g = 9.81 m/s²

Enter a value on the left and press Calculate

Summary

Enter a height (or time) to instantly calculate free-fall duration, final velocity, and distance fallen under gravity.

How it works

Select your preferred unit system: metric (meters) or imperial (feet).
Choose a calculation mode: solve from height, from time, or from final velocity.
Enter the known value in the input field.
Results for the other two quantities appear instantly.
Use the "Reset" button to clear all fields and start over.

Use cases

Physics homework and exam practice on kinematics.
Engineering estimates for drop tests and safety distances.
Checking how long an object takes to fall from a known height.
Converting between fall time, velocity, and distance quickly.
Teaching or demonstrating gravitational acceleration concepts.
Calculating impact velocity before a drop experiment.

Frequently Asked Questions

Last updated: 2026-06-09 · Reviewed by Nham Vu