What immersed weight means
When an object is submerged in a fluid, it feels lighter due to buoyancy — this is Archimedes’ principle. Immersed (apparent) weight is the object’s weight in air minus the buoyant force pushing it upward.
The formula
Weight in air = ρobject × V × g. Buoyant force = ρfluid × V × g. Immersed weight = weight in air − buoyant force, where V is the object’s volume, g is gravitational acceleration (9.80665 m/s²), and ρ represents density.
This calculation assumes the object is fully submerged and denser than the fluid; if the object would float, its true submerged weight is zero (it wouldn’t sink at all).
Last reviewed August 2026