Some interchangeably use mass and volume probably because they are both used to measure objects. Mass refers to the amount of matter than one object may have while capacity refers to the amount of space than an object takes up. There are different formulas that you can use to help you determine the actual mass or the volume of an item.

For example, mass is equal to volume times density. If you want to solve for volume, you need to use the formula for mass divided by density. The answer will differ depending on the given numbers. Now that you know that they are not the same, it will be easier for you to determine which is which.