Terminal Velocity Calculator

When an object falls through a fluid, gravity accelerates it downward while air resistance pushes back up. The drag force increases as the object speeds up, and at some point the two forces balance exactly. From that moment, the object stops accelerating and falls at a constant speed called the terminal velocity. The formula for terminal velocity is the square root of two times mass times gravity divided by the product of fluid density, drag coefficient, and cross-sectional area: vt equals the square root of (2mg divided by rho times Cd times A). Each factor plays a clear physical role. A heavier object needs more drag to slow it down, so it reaches a higher terminal velocity. A larger cross-sectional area creates more drag at a given speed, so it lowers terminal velocity. A higher drag coefficient, which reflects a blunter or less streamlined shape, also lowers terminal velocity. Higher air density increases drag and reduces terminal velocity, which is why terminal velocities are lower at sea level than at altitude. A skydiver in a belly-to-earth position presents a large area (roughly 0.9 m2) with a drag coefficient of about 1.0 and reaches about 53 m/s (190 km/h). Pulling into a head-down dive reduces area to around 0.1 m2, raising speed to well over 90 m/s. This calculator accepts mass, drag coefficient, cross-sectional area, and fluid density as inputs, with presets for common scenarios. It returns terminal velocity in m/s and km/h, drag force at terminal velocity (which equals weight), and power dissipated by drag at terminal speed.

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Air density at sea level and 15 °C is approximately 1.225 kg/m³. Drag coefficient varies with shape, surface roughness, and Reynolds number. Results are for estimation only.