You're way off. Cash flow is about flow and timing: Factors like how fast you pay and how fast you get paid are vital, but you know nothing of that by just knowing the sales, costs and expenses.

I've done a 20-minute free video for you, online, that will explain how cash flow works. Please take a look at http://timberry.com/videos/. It's vital, too. Take the time to get this right, or bring on a team member, because cash is what runs your business.