Body Mass Index is one of the best known methods for analyzing body fat in adults, based upon their height and weight. The skin calipers I created allow astronauts to track their BMI on the trip to Mars by measuring the widths of fatty skin in key areas such as the abdominal and chest. This creation would allow astronauts to make sure their bodies are still performing at peak level, and that they are not hitting extreme levels of fat while in space and living off non-traditional meals. If the space readings differ too much from readings taken on Earth, precautions can be taken to ensure their safety. A simple .25" diameter fastener can be inserted into the hole to allow a snug rotation, and a rubber band/spring can be strung between the two pegs in order to provide resistance and allow the calipers to tightly grip the skin in order to provide an accurate reading. The two differently colored bodies should be 3D printed as separate pieces, so that they can fit in the 6 inch build volume.