What does it cost to provide a bachelor's-level education? This question arises with increasing frequency and urgency as pressure mounts on policymakers and education leaders to increase the education attainment level in the United States, to "Double the Numbers" in some cases. At the same time, the two traditional sources of financing--state appropriations and private tuition payments--show signs of being stretched to their limits. Yet determining the cost of a degree is not a simple question to answer in a system that has made enrollments--i.e., the credit hour, the FTE--the primary unit of accounting, rather than the completed degree. Even with credit hours, only a minority of state systems, such as Florida, Illinois and Minnesota, routinely analyze instructional costs at a level of detail beyond institution and instructional level totals. While there has been considerable effort invested in analyzing college costs, no consensus or common language has emerged to describe how the cost of a degree should be measured. Consensus around a single method may be neither possible nor desirable, given the range of different policy contexts in which the question comes up. A common language, however, could help keep discussions of the issue more focused than they often are. This paper suggests the beginnings of that language by briefly outlining five approaches to degree costs: (1) Catalog cost; (2) Transcript cost; (3) Full cost attribution; (4) Regression-based cost estimates; and (5) Student's cost of a degree. Appended are: (1) Detailed tables; and (2) SPSS scripts and output for stepwise regression analysis. (Contains 23 tables and 22 footnotes.) [Funding for this paper was provided by Making Opportunity Affordable, an initiative of Lumina Foundation for Education.]