Austin, TX: $53,225 

Income needed: $53,225

50 percent for necessities: $26,612

30 percent for discretionary spending: $15,967

20 percent for savings: $10,645

Most residents of Austin can live comfortably on the city's median income, which at $55,216 is $1,991 above the salary needed to follow the 50-30-20 rule.