To determine the variables cost, view on their purpose. For example, you purchased any material that goes into production, that is, he directly participated in the release. Let it be wood, which produce lumber of various sections. From the amount of purchased wood will depend on the volume of produced lumber. Such costs relate to variables.
In addition to the wood you use electricity, the amount of which also depends on production volume (the more you produce products, the more you spend kilowatts), for example, when working with the sawmill. All of the expensesthat you will pay the company supplying electricity, also relate to variable costs.
To produce products that you use labor, which must pay wages. These costs relate to variables.
If you do not have own production, and act as an intermediary, that is, resell previously purchased goods, the total purchase price related to variable costs.
To determine the variables costs, analyze the dynamics of increase in all costs. As a rule, they will increase when the volume of production will rise, and conversely, decrease when decrease in performance.
To understand what it means to variables costs, consider permanent. For example, the rent of the premises does not affect the volume of production. These expenses and are permanent. Salary management staff is also not always depend on the output, then as an employee of the shop gets is proportional to the volume of products manufactured.
In variables expenses include deductions for social needs of the employees production; fuel, water. All of that affects the volume.