An overview of the general cost of living index for Castle Rock, CO is displayed above for your reference. Residents in Castle Rock, CO enjoy a cost of living index of 121. This index is 10% higher than the Colorado average, and 21% higher than the national average. The following categories are used when determining the cost of living index for any given city: health care (5%), transportation (9%), utilities (10%), groceries (13%), housing (30%), and goods/services (33%). Clearly, housing and goods/services make up the majority of the formula for calculating the cost of living index. Because of this, the general cost of living for any given area can be estimated by looking at the cost of everyday goods in that area. For those living in Castle Rock, CO, the average cost of goods and services is 5% higher than it is in Colorado, and it is 9% higher than the national average.