Cost Accountant Salary. (United States). A Cost Accountant earns an average salary of $52,624 per year. People in this job generally don't have more than 20 years' experience. A skill in SAP Enterprise Resource Planning (ERP) is associated with high pay for this job.he cost accountant should be able to determine and explain the factors that will cause costs to vary; strong research skills are essential to determine all of the costs associated with certain decisions.