AUSTIN (KXAN) — Austin is one of the fastest-growing cities in the country, but a new report suggests explosive growth is only just beginning.

The city recently climbed into the top 10 largest cities in the U.S., with a 2022 population estimate of about 975,000.

In the 2020 census, the Austin metro as a whole had more than 2.2 million residents. The metro is defined by the U.S. Census Bureau as Bastrop, Caldwell, Hays, Travis and Williamson counties.

A new report by moving company MoveBuddha predicts that by the end of the century, the Austin metro will jump to the third-largest in the country, behind only Dallas/Fort Worth and Houston. That means all three would surpass the current largest metro areas, like New York, Los Angeles and Chicago.

The report suggests the Austin metro’s population would skyrocket, from 2.2 million in 2020 to more than 22 million by 2100. The Dallas/Fort Worth and Houston metros would have more than 30 million people each.

But those numbers are far greater than what Austin city demographers are forecasting. Projections from the city suggest the metro’s population will hit 4.3 million in 2060, well below the 7.2 million forecast by MoveBuddha’s report.

The city currently does not project populations beyond 2060.

So why is there such a large discrepancy between the city’s projections and the moving company’s report? The answer lies in the methodology of how MoveBuddha made its forecast.

The report says, “MoveBuddha applied 2010-2020 Census growth rates to project the top 10 U.S. metropolitan areas in 2100.” Between 2010 and 2020, the Austin metro’s population grew by a third.

In its forecast for the future, the company applied that same growth rate to every decade moving forward, meaning migration trends would stay the exact same as they are now. So between 2020 and 2030, the metro’s population would increase by a third, then between 2030 and 2040, it would increase by a third again, and so on. That is represented by the green line in the chart below.

But migration trends staying the exact same is highly unlikely. The yellow line above shows the city of Austin’s forecast for future growth.

City demographers believe the metro will grow by about 23% between 2020 and 2030, then by a further 18.5% by 2040, an extra 15.6% by 2050 and an additional 13.5% by 2060.

Or, put another way, city projections show the Austin metro’s population will grow by about 90% over the next four decades, while MoveBuddha’s report says it will grow by more than 210% during that same timeframe.

Over the past 40 years, the metro’s population grew by 290%, from less than 600,000 in 1980 to more than 2.2 million in 2020.