Calculating and using a Single Charging Rate The expected costs for the Maintenance Department of Stazler, Inc., for the coming year include: Fixed costs (salaries, tools): $64,900 per year Variable costs (supplies): $1.35 per maintenance hour Estimated usage by: Assembly Department 4,500 Fabricating Department 6,700 Packaging Department 10,800 Total maintenance hours 22,000 Actual usage by Assembly Department 3,960 Fabricating Department 6.800 Packaging Department 10,000 Total maintenance hours 20,760 Calculating and using a Single Charging Rate The expected costs for the Maintenance Department of Stazler, Inc., for the coming year include: Fixed costs (salaries, tools): $64,900 per year Variable costs (supplies): $1.35 per maintenance hour Estimated usage by: Assembly Department 4,500 Fabricating Department 6,700 Packaging Department 10,800 Total maintenance hours 22,000 Actual usage by Assembly Department 3,960 Fabricating Department 6.800 Packaging Department 10,000 Total maintenance hours 20,760