Any object, wholly or partially immersed in a fluid, is buoyed up by a force equal to the weight of the fluid displaced by the object -- Archimedes of Syracuse.
Archimedes' Principle formula:
F = V * g * (ρf - ρ0)
V: Volumen of the Object, in m3
F: Buoyant force of the object, in Newton
g: acceleration due to gravity, is 9.80665m/s^2
ρf: Density of the object
ρ0: Density of the fluid