The notion of the formula is foundational to our understanding of Old English poetics and to the way we read Old English poetry. Both its definition and its implications for the aesthetic concerns of Old English poets have been long debated. My aim in this chapter lies not with the conventionality or originality of Old English poetry – which is often at issue in discussions of the formula; rather I intend to problematize the notion that we can define the formula, and then, from this perspective, to consider Old English poetic aesthetics. Collocation allows the formula to be looked at from a range of perspectives, particularly the semantic, the lexical, the syntactic, the metric, the contextual and, of special interest here, the stylistic. Style is a component absent from definitions of the formula, in part because an assumption of utilitarian function has often been a starting point. Meter will not be addressed in a separate section but its consideration will inevitably run throughout the discussion which follows. By drawing on the material presented in the previous chapter, which provides detailed study of specific formulas, I will argue that we need to think in terms of a range of kinds of formulas which overlap with, and often cannot be separated from, other kinds of more stylistically driven verbal repetitions, on the one hand, and patterns found in everyday linguistic expression, on the other.