<span>Density is calculated by dividing an object’s mass by its volume. Density is less intuitive than mass or volume, but if you have ever picked up an object and found it much lighter or heavier than you expected, that’s because its density is not what you thought. Density usually can’t be measured directly and must be calculated after mass and volume have been determined. Density is sometimes used to describe other quantities divided by volume, such as energy density.</span>
