Variable cost

Variable cost is any costs of production that increases with the quantity produced.

Definitions

According to Principles of Economics by Timothy Taylor (3rd edition),

Variable costs. Costs of production that increase with the quantity produced.

According to Marketing Management by Keller and Kotler (15th edition),

Variable cost. Cost that varies directly with the level of production.

According to Cost Accounting by Horngren, Datar, Rajan (14th edition),

Variable cost. Cost that changes in total in proportion to changes in the related level of total activity or volume.

According to Product Manager's Handbook by Gorchels (2nd edition),

Variable costs. Those costs that vary directly with the level of production. They tend to be constant per unit produced.

According to Managerial Accounting by Braun, Tietz (5th edition),

Variable costs. Costs that change in total in direct proportion to changes in volume.