Buoyant Forces Are Everywhere

Let the volume of the average human be $v$ . This is the volume of air that the human displaces. The mass of air displaced is then $\rho v$ , where $\rho$ is the average density of air. The weight of air displaced is $\rho v g$ , and this is the amount of buoyant force experienced by the human being.

We can assume our body's density to be equal to density of water since our body is mostly made of water. If the mass of the human being is $\SI{75}{\kilogram}$ , then the volume occupied is $75$ litres, or $\SI{75e-3}{\meter ^3}$ . The density of air is about $1.23 \text{ kg/m} ^3$ . Hence the weight of air displaced is $1.23 \times \dfrac{75}{1000} \times 9.81$ $= \SI{0.905}{\newton}$

The average human being experiences a buoyant force of about $\SI{0.905}{\newton}$ . This is of the order of magnitude of $\SI{1}{\newton}$ .