How to Measure the Density of a Person

By Ess Loumarr; Updated April 24, 2017

The density of a human body is the measurement of the amount of mass present in each unit of the body’s volume. The density of most objects can be studied in relation to water, which has a density of 1.0 gram per cubic centimeter. Objects with a density greater than 1.0 will sink in water, while less dense objects float. Under different circumstances, the human body is capable of either sinking or floating in water, which indicates the density of a person is close to 1.0 g per cubic centimeter.

Instructions

Use a scale to get an accurate measurement of the person’s weight. Convert the measurement from pounds to grams. One pound is approximately 453.59 grams, so multiply this value by the calculated weight. The converted measurement represents the individual’s mass.

Fill a bathtub or a large basin with water, making sure the water level is high enough to accommodate a full submersion. Mark the initial water level with a piece of tape. Have the person enter the tub and immerse their entire body underwater, leaving no more than their head above water. For the most accurate volume measurement, wear goggles and a snorkel so that the person is fully submerged. The water level should rise when the person sits down in the tub.

Mark the new water level with another piece of tape. Remove the excess water with the measuring cup until the water level reaches the first tape mark. Use the measuring cup to keep track of how much water is removed, and place a bucket nearby to dispose of the water. The displaced water represents the person’s volume. (Note: It may be necessary for another person to perform this task while the experimenter is submerged.)

Convert the volume into cubic centimeters. If the initial volume was measured in cups, the conversion ratio is approximately 236.59 cubic centimeters to one cup. If measured using a gallon bucket, the ratio is 3,785.41 cubic centimeters to one gallon.

Determine the person’s density by using the following formula: density = mass/volume. If measured accurately, the resultant value should be close to 1.0. The overall value depends on the body type of the person who performs the experiment, as muscle is more dense than body fat.

Tip

If this experiment or a variation is performed in a classroom environment, remember to follow all safety rules designated by the educational institution.

About the Author

Ess Loumarr is a freelance writer from New England and has worked as a copywriter since 2008. Her short fiction has appeared in the "Spectrum Anthology" at the University of California, Santa Barbara. She received a Bachelor of Arts in English literature and composition at Columbia University, as well as prizes for playwriting and fiction.