The average CPC is determined by simply dividing the total ad costs by the total number of clicks:
The maximum CPC bid is the highest amount you are willing to pay per click for your ad. Only in extreme cases is the CPC higher than the maximum CPC bid - usually the CPC is lower than the maximum CPC bid. If Google awards a high purchase probability of your products to a certain search query, the maximum CPC is raised once only. As the total costs of your marketing campaign depend on the total amount of clicks received, the optimization of your CPC is vital.