We caught up with Rhett on Taste of Country Nights to get the answer straight from him, and he happily answered.

"I mean, five has kind of always been our number," the "Die A Happy Man" singer said. "Anything above 5, we will have to get a Sprinter van."

Rhett says that even if baby No. 5 turns out to be another girl, he and Lauren plan to stop at five children since that's the number they've always talked about as a couple.

When it comes to baby No. 5, the couple exclusively told Taste of Country that they're waiting until the birth in March to learn the gender. Rhett admits that decision has him feeling "a little nervous," but they're excited to be surprised.

"If it's a boy, we definitely need to change some of the nursery wallpaper, because it's pretty girly," Rhett says. "We'll need to put some footballs on the wall or something like that."

It's easy to imagine just how pink and playful the Rhett household must be between Lauren and their four daughters, Thomas Rhett is definitely outnumbered. Chances are, he's carved out a little mancave somewhere to claim as his own.

Don't expect the "Life Changes" singer to make any major life changes when it comes to his ride. Rhett jokes, "I'm not in a dad-wagon -- I'll still drive a truck."

Rhett's wife's name is Lauren and the two have known one another since grade school. They tied the knot on Oct. 12, 2012.