You won't get a straight answer but you can often ballpark it if you work there or know someone who does. I have friends at McDonalds and Dominoes, where the owners were making ~$50 and ~$80 per labor hour, respectively, iirc. That's profit after all known non-labor expenses.
I make it a point to figure this out for every place I or a friend works at, and then make sure everyone who works there knows the real numbers. Because bourgeois fucks will act like money's tight and lie to your face, so knowing the truth is necessary for convincing workers they can collectively bargain for more.