piece-rate and commission costs. Note that some businesses pay workers on a piece-rate or commission basis. All your costs that vary with each sale should be in cost of sales instead of fixed expenses.     When youve completed your cost of sales calculations, you are ready to prepare your Profit and Loss Forecast. D. Complete Your Profit and Loss Forecast     You will find a blank Profit and Loss Forecast form in Appendix 4. Follow the line-by-line instructions below to complete your form.     NoteNote for computer users: If you want to use a computer spreadsheet instead of the Profit and Lost Forecast form, set it up with all of the same categories as the blank Appendix 4 form.     1.Sales Revenue. You have completed this estimate already. Simply enter the total sales revenue dollars for each month for two years from the Sales Revenue Forecast you completed   WarningHeres another chance to revise the sales revenue numbers in case you think they need work. However, be sure you really believe that you can generate all the revenues you forecast. Make sure you dont do it backwards by writing down enough sales revenue to show the profits you want. Otherwise, youll have to explain to your backers each month why things arent as good as you said they would be.     2.Cost of Sales. Enter your monthly dollar cost of sales. To get these figures, multiply your monthly sales revenue forecast by the average cost of sales percentage you developed in C, above. Returning to our dress shop example, Antoinette would multiply her monthly sales figure estimate by 60% (or 0.6). For example, if March sales are forecast at $30,000, the cost of sales for March would be $18,000 (0.6 x 30,000 = 18,000).     WarningIf you made separate forecasts of sales revenue, cost of sales and gross profit for each product line, then add together all the gross profit numbers and enter them on a summary form line 3. You will have prepared separate forms for each product line for the first three lines (sales revenue, cost of sales and gross profit) and a summary sheet showing total gross profit, operating expenses and profit.     3.Gross Profit. Subtract cost of sales (line 2) from sales revenue (line 1) to get gross profit. Its the amount of money that remains after youve paid your direct costs of the products sold. This money is available to pay the business fixed expenses and your profits. If gross profit is larger than fixed expenses for that month, you will have a profit. But if gross profit is smaller than fixed expenses, you will have a loss that month.     For example, looking at the dress shop example for March, Antoinette arrives at gross profit by subtracting the cost of sales of $18,000 from the forecast sales revenue of $30,000 and entering the result of $12,000. Shell do the same thing for each subsequent month.