Buoyant Force Calculator

About this calculator

This calculator finds the buoyant force on a submerged or floating object using Archimedes' principle: F = ρ·g·V, where ρ is the fluid's density, g is gravitational acceleration, and V is the volume of fluid displaced. The result equals the weight of the fluid the object pushes out of the way, which is also the mass of fluid displaced multiplied by g.

Naval architects, engineers, and physics students use this to size ballast tanks, check whether a hull or hot-air balloon will float, and to solve textbook problems on floating versus sinking objects. Enter the fluid density (water, seawater, or air), the submerged volume, and gravity to get both the buoyant force and the displaced mass.