When it comes to running a business, you have to know your numbers, says Marcus Lemonis, star of CNBC's "The Profit."
The serial entrepreneur, who puts his own cash into struggling businesses and tries to turn them around, would know. At this point, he's invested about $35 million in companies featured on the show.
Regardless of the size of your company, every business owner needs to know three numbers, Lemonis says:
1. Your annual sales revenue, "based on a trailing 12 months, not the calendar."
2. Your gross profit margins.
3. And your expenses as a percentage of your gross profit — "not a percentage of your sales. You pay your bills with gross profit — not with revenue."