When does a firm break even under perfect competition?

A firm breaks even under perfect competition when its total revenue equals its total costs, which occurs at the point where the price of the product equals the average total cost (ATC). This situation typically happens in the long run, as firms enter or exit the market until economic profits are zero. At this point, firms cover all their costs, including opportunity costs, but do not earn economic profit. Thus, the firm operates at the minimum point of its ATC curve.