Startup costs fall into two categories: one-time costs (equipment, registration fees, initial inventory) and recurring monthly costs (rent, salaries, utilities, subscriptions) -- underestimating the second category is one of the most common reasons new businesses run out of money. The break-even point is the sales volume at which total revenue equals total costs, calculated by dividing fixed costs by the profit margin per unit; for example, a business with ₦2,000,000 in fixed monthly costs and a ₦5,000 profit margin per unit needs to sell 400 units a month just to break even. Cash flow -- the actual timing of money coming in and going out -- is different from profit on paper: a business can be profitable overall but still fail if customers pay late while suppliers and staff must be paid on time. Building a simple month-by-month cash flow projection, even in a basic spreadsheet, reveals these timing gaps in advance so you can arrange a buffer or adjust payment terms before a cash shortage becomes a crisis.