Measurement	Definition	Mathematical term
Short run	Fixed cost	Cost that does not depend on the quantity of output produced	FC
	Average fixed cost	Fixed cost per unit of output	AFC = FC/Q
Short run and long run	Variable cost	Cost that depends on the quantity of output produced	VC
	Average variable cost	Variable cost per unit of output	AVC = VC/Q
	Total cost	The sum of fixed cost (short run) and variable cost	TC = FC (short run) + VC
	Average total cost (average cost)	Total cost per unit of output	ATC = TC/Q
	Marginal cost	The change in total cost generated by producing one more unit of output	MC = ΔTC/ΔQ
Long run	Long-run average total cost	Average total cost when fixed cost has been chosen to minimize average total cost for each level of output	LRATC