基数效用（Cardinal Utility）是指像个人的体重或身高那样在基数的意义上可以度量的效用（它意味着效用之间的差别，即边际效用，是有意义的）。序数效用与它相反，它只在序数的层面上才有意义。

In economics, a cardinal utility function or scale is a utility index that preserves preference orderings uniquely up to positive affine transformations. Two utility indices are related by an affine transformation if for the value of one index u, occurring at any quantity of the goods bundle being evaluated, the corresponding value of the other index v satisfies a relationship of the form