What is terminal velocity?

Terminal velocity is the maximum speed a falling object reaches when gravitational force equals the drag force opposing its motion. At that point net force is zero, so speed stays constant.

What drag coefficient should I use?

Common values: sphere ≈ 0.47, cylinder ≈ 0.82, flat plate ≈ 1.17, streamlined body ≈ 0.04, skydiver (belly-to-earth) ≈ 1.0. The lower the Cd, the less drag and the higher the terminal velocity.

Why does a heavier object sometimes fall faster?

A heavier object has more gravitational force. If its shape and cross-section are the same as a lighter one, it needs to reach a higher speed before drag balances gravity — hence a higher terminal velocity.

What is the standard air density used?

The default is 1.225 kg/m³, which is the International Standard Atmosphere value at sea level and 15 °C. Air density decreases with altitude and temperature, so you can adjust it for more accurate results.

Does this account for altitude or varying gravity?

This calculator uses standard gravity (9.80665 m/s²) and lets you set any fluid density manually. For high-altitude scenarios, lower the density to match. Gravity variation is small enough to ignore for most practical cases.

Terminal Velocity Calculator

Enter mass, drag coefficient, cross-sectional area, and fluid density to instantly calculate terminal velocity.

Object Parameters

Fill in the values below or pick a preset.

Presets

Mass (kg)

Drag Coefficient (C_d) (dimensionless)

Cross-sectional Area (m²)

Fluid Density ρ (kg/m³)

Air at sea level = 1.225 kg/m³

Results

Enter values and click Calculate

Summary

Terminal velocity is the constant speed a falling object reaches when the drag force equals gravitational force, so acceleration becomes zero. This calculator applies the standard physics formula v_t = sqrt(2mg / (rho * Cd * A)) to find that speed given the object's physical properties. It covers objects falling through air at sea level or any custom fluid density.

How it works

Enter the mass of the falling object in kilograms.
Enter the drag coefficient (Cd) — a dimensionless shape factor (e.g. 0.47 for a sphere).
Enter the cross-sectional area in square meters (the projected area facing the flow).
Optionally adjust fluid density — air at sea level is 1.225 kg/m³ by default.
Click Calculate to get terminal velocity in m/s, km/h, and mph.
Use the preset buttons to populate common object values instantly.

Use cases

Estimate skydiving terminal velocity for a person in various body positions.
Calculate how fast a raindrop, hailstone, or snowflake falls.
Physics homework and lab report verification.
Engineering analysis of free-falling components or debris.
Compare terminal velocities across different shapes and sizes.
Understand how parachute area reduces landing speed.
Model projectile descent in aerospace or sports science.

Frequently Asked Questions

Last updated: 2026-06-13 · Reviewed by Nham Vu