To find the density of an object, you must first determine its volume. You cannot convert mass to density without knowing the volume. Mass is the amount of matter in an object and density is the ratio of mass to its volume. An object that is considered very dense has tightly compacted matter, and a less dense object has matter that is spread apart. In order to find volume, you will need a measuring tape and calculator for accuracy.

## Rectangular Object

Write down this equation: Density = Mass / Volume. Substitute the mass of your object in grams for the word Mass in this equation.

Find the volume of the object. Measure the object's width, height, and length in centimeters.

## Sciencing Video Vault

Multiply these three measurements together to get your object's volume.

Divide your Mass number by your Volume number to get the Density of your object.

## Spherical Object

If the object is spherical, use the equation V=(4/3)3.14*r^3 to find the volume.

Find the radius of the sphere, which is the distance from the center to the outer edge. Plug in this number for "r" and calculate the equation.

Divide your Mass number by your Volume number to get the Density of your object.