Determine the weight of the object in air
Determine the apparent weight of the object when submerged in a fluid
Subtract the apparent weight from the weight in air
Use the formula: Buoyant Force = Weight in air – Apparent weight in fluid
Alternatively, use the formula: Buoyant Force = density of fluid × volume displaced × gravitational acceleration
Measure or calculate the volume of fluid displaced by the object
Multiply the fluid density, displaced volume, and gravitational acceleration to get the buoyant force