How do you measure body volume? I need two ways. Thanks.

Question

Displacement is a common method. Fill a barrel full of water, then dunk the body (letting the water overflow), remove the body, and then measure the water level.

Another method is to use air displacement, by Air Displacement Plethysmography, which uses sound changes in a resonant cavity. This is very often used for premature infants.

Thanks for your response. Is there another way other than using an Air Displacement Plethysmography? Something that can be done at home?
Thanks again.

Yes. It is a modification of the displacement method. It involves weighing the body when submerged (it will be negative if the person can float) and the weight when not in water. This difference, with the density of water (corrected for temperature of water) can give you the vollume of water displaced, or the volume of the body.