[NBTX11]

^^There are 8 total cities with 5 million plus, and 12 total with 4 million plus, so a combined SA/Austin would rank around 14th or 15th in the US in terms of metro population, if they combined metros. (I know, they aren't currently combined)

1 New York–Northern New Jersey–Long Island NY–NJ–PA 18,747,320
2 Los Angeles–Long Beach–Santa Ana CA 12,923,547
3 Chicago–Naperville–Joliet IL–IN–WI 9,443,356
4 Philadelphia–Camden–Wilmington PA–NJ–DE–MD 5,823,233
5 Dallas–Fort Worth–Arlington TX 5,819,475
6 Miami–Fort Lauderdale–Pompano Beach FL 5,422,200
7 Houston–Sugar Land–Baytown TX 5,280,077
8 Washington–Arlington–Alexandria DC–VA–MD–WV 5,214,666
9 Atlanta–Sandy Springs–Marietta GA 4,917,717
10 Detroit–Warren–Livonia MI 4,488,335
11 Boston–Cambridge–Quincy MA–NH 4,411,835
12 San Francisco–Oakland–Fremont CA 4,152,688
13 Riverside–San Bernardino–Ontario CA 3,909,954
14 Phoenix–Mesa–Scottsdale AZ 3,865,077
15 Seattle–Tacoma–Bellevue WA 3,203,314