ACSI (American Customer Satisfaction Index) Score & Its Calculation
Posted by Jeffrey Henning on Wed, Mar 11, 2009
The American Customer Satisfaction Index (ACSI) is the most well known national customer satisfaction index model, a type of economic indicator that assesses the overall satisfaction of consumers in a country. The ACSI is compiled by the National Quality Research Center (NQRC) at the University of Michigan. While intended as a macroeconomic measure of U.S. consumers in general, many corporations have used it to measure the satisfaction of their own customers.
The heart of the American Customer Satisfaction Index is a set of three questions that assess satisfaction, each on a different 10-point scale:
Some organizations normalize and average the three ratings, like this:
(Satisfaction + Expectancy + Performance - 3) / 27 * 100
This produces an overall score from 0 to 100 that can be used as an approximate benchmark to industry results published by TheACSI.org.
The true ACSI customer-satisfaction score is a weighted average of the answers to each of these three questions, using a proprietary weight for each of the three questions, with different weighting schemes for different industries. For instance, overall satisfaction is typically given a higher weight than expectancy, which is given a slightly higher weight than performance. The State of Ohio uses the following weights:
((Satisfaction-1)*.3885 + (Expectancy-1)*.3190 + (Performance-1)*.2925) / 9 * 100
If you want the precise results for your industry, you will want to commission a custom ACSI research program with ACSI, for $50,000; this will include the precise question wording and survey methodology used for gathering the benchmark data. Otherwise the above question phrasing and calculation can be used for a Do-It-Yourself customer-satisfaction index and benchmark.