By NEAL WAGNER / Managing Editor

Shelby County residents have the highest purchasing power in the state by a relatively large margin, according to a study recently completed by the Smartasset.com website.

The website studied the average living expenses for all Alabama counties, and looked at cost of living compared to income to determine overall purchasing power.

“First, we calculated two different cost of living numbers for a household with one adult and no dependents. One reflected the baseline cost of living in each area and the other was based on expenditures typical to someone making the county’s median income,” read the site. “We combined the two cost of living numbers using a weighted average based on how close each county’s median income was to the minimal livable income in that area. We then subtracted income taxes paid in that area. Finally, we calculated purchasing power by determining the weighted cost of living as a percentage of median income.”

Shelby County had the highest cost of living on the list, but also had the highest median income by a significant margin compared to other counties in the top 10 to earn the website’s highest “purchasing power index.”

Shelby County has an average cost of living of about $45,334 and a median income of about $74,063, leading to a purchasing power index of 71.99.

Madison County in north Alabama came in at No. 2 on the list, with a $38,800 average cost of living, a median income of $61,318 and a purchasing power index of 69.63.

Coffee County in southeast Alabama came in at No. 3, with an average cost of living of $34,276, a median income of $49.821 and a purchasing power index of 62.76.

Autauga County north of Montgomery placed No. 4 on the list, with an average cost of living of $38,838, a median income of $55,317 and a purchasing power index of 62.76.

Rounding out the top five was Morgan County in north Alabama, which had an average cost of living of $33.461, a median income of $47,529 and a purchasing power index of 62.59.

Limestone, Elmore, Lee, Jefferson and Dale counties rounded out the top 10.

To view the entire study, visit Smartasset.com/mortgage/cost-of-living-calculator#alabama.