Assume a firm produces clothing. When the quantity of the output varies from 5 shirts to 10 shirts, fixed cost would be 30 dollars. In this case, average fixed cost of producing 5 shirts would be 30 dollars divided by 5 shirts, which is 6 dollars. In other words, when 5 shirts are produced, 30 dollars of fixed cost would spread and result in 6 dollars per shirt. Similarly, average fixed cost of producing 10 shirts would be 3 dollars derived from 30 dollars divided by 10 shirts.
A table and graph of average fixed cost
In Example1, there was no information about average total cost and average variable cost. If the firm knows average total cost and average variable cost, it is possible to find the same result as Example 1. Because average total cost is average variable cost plus average fixed cost, average fixed cost is average total cost minus average variable cost. If producing 5 shirts generates average total cost of 11 dollars and average variable cost of 5 dollars, fixed cost would be 6 dollars. Similarly, the firm produces 10 shirts and average total cost and average variable cost is 10 dollars and 7 dollars respectively. In this case, average fixed cost would be 3 dollars.