operating profit of $17,600 per month. (Abbreviation used; CM= contribution margin.) Read the equirements. 10. Calculate the required sales in units to earn the target profit using the equation method. First, select the formula to compute the target profit. Net sales revenue Variable costs Fixed costs Target profit Rearrange the formula you determine above and compute the required sales in units. The required sales in units to earn the target profit using the equation method is Requirements 10. Calculate the required sales in units to earn the target profit using the equation method. 11. Calculate the required sales in units to earn the target profit using the contribution margin method. 12. Calculate the required sales in dollars to earn the target profit using the contribution margin ratio method. 13. Calculate the required sales in units to break even using the contribution margin method