Most people think of the cost of a library in terms of its assigned bu
dget, which sets out the annual allocation of specific sums of money f
or specific purposes. This budget is only symbolic since, in many case
s, certain kinds of expenditures are not included, and some, such as o
pportunity costs, cannot, because of their nature, be included in a fi
nancial statement. In addition, a relatively new concept, ''value main
tenance,'' should be considered. Almost all writing by academic librar
ians has been concerned with operating budgets rather than the total c
osts of libraries. Here an attempt will be made to review the kinds of
costs involved and how they affect the real cost of running a library
. For the most part, first attention will be given to academic librari
es, but, where appropriate, reference will be made to other libraries.