P*Q = VC*Q+FC+Operating Profit
where P is the sales price per unit, Q is the quantity produced and sold, VC is the variable cost per unit
and FC is the total fixed costs. As can be seen from the above equation the sales revenue is the product of the sales price per unit and the quantity sold. The sales revenue equals the variable costs of the products plus the total fixed costs and the operating profit. At a zero profit the break-even point is calculated which shows the quantity required to be produced and sold to cover up all the fixed and variable costs of the business.