Density is the mass per volume of a given substance. The most common unit for density is grams per milliliter. Density is a physical property and is often used during science experiments when a substance needs to be identified. If you understand the density equation, then you can solve for either the mass or the volume of the substance. In order to convert density to grams, write down the information that you are given and the density equation, solve for the mass and then multiply the density by the volume.

Write down the information that you are given. If you are converting the density to grams, then you know the density and the volume. For example, the density may be 2 g/mL, and the volume may be 4 mL.

Write down the density equation. Writing down the equation will help you to decide how to solve for the correct variable. The equation for density (d) is the mass (m) divided by the volume (v). Therefore, d = m/v.

Solve for the mass. In order to convert density to grams, you have to put the mass on one side of the equation, and the density and the volume on the other. Therefore, d * v = m.

Multiply the density by the volume. Using the example in step 1, you would multiply 2 g/mL by 4mL. You should receive an answer of 8 grams for the mass.