Chick-fil-A may grow its U.S. sales faster over the next decade than McDonald’s Corporation, according to Mark Kalinowski, a restaurant industry analyst.  He estimates that Chick-fil-A could gain between $6.3 billion and $9 billion in U.S. sales by 2023. Domestic sales for Oak Brook-based McDonald’s, he predicts, could increase anywhere between $1 billion and $10.5 billion.

Between 2003 and 2013, Atlanta-based Chick-fil-A expanded its domestic sales from $1.5 billion to $5 billion, the Kalinowski said, by building new stores and increasing in-store sales. It has overtaken KFC as the market leader in the limited-service chicken category, with 26.3 percent of the share compared with KFC’s 21.9 percent.

Chick-fil-A has particular room for more growth in heavily populated northern states that do not have many of the restaurants there yet, Kalinowski said. “While Chick-fil-A remains meaningfully smaller than McDonald’s U.S. today, to the extent it could be ignored as a competitive threat ten years ago, we would argue that it can no longer be ignored as a long-term competitive threat today,” he wrote.

“Our growth is attributed to having millions of customers who are loyal to the brand,” said Chick-fil-A spokeswoman Brenda Morrow. “It is gratifying to see that demand for our food and service is growing, and we are happy to meet the demand.”

Chick-fil-A plans to open 103 restaurants this year and enter two new markets, Rhode Island and Connecticut, Morrow said.