Underwater Weighing Sample Calculations

Here is a chance to observe how changes in some of the variables will affect the calculations for body density and percent body fat. In the forms below, try varying the values for body weight, underwater weight, water temperature, and residual lung volume.

1. Enter the subject's weight in air (in kilograms):


This can be any positive value.
Typically, we would expect values between 30.00 kg and 250.00 kilograms.

2. Enter the subjects weight underwater (in kilograms):


Report this value to the nearest 0.01 kg.
Typically, this value would be between -3.50 and +5.00 kg.
Remember, an individual can weigh less than zero underwater. Why?

3. Select the temperature of the water in the tank (degrees Centigrade):


This form will automatically assign the corresponding density of water for the selected temperature.

4. Enter the residual lung volume (in liters):


Typically, this value is between 1.000 and 2.000 liters.

Result:

Enter the subject's body density value:


The value from the above calculation will be entered by default.
Or, you can enter any value you choose.

Result: