Let H be a commutative and cancellative monoid. The elasticity ρ(a) of a non-unit a ∈ H is the supremum of m/n over all m, n for which there are factorizations of the form a = u 1 · . . . · um = v 1 · . . . · vn, where all u i and v j are irreducibles. The elasticity ρ(H) of H is the supremum over all ρ(a). We establish a characterization, valid for finitely generated monoids, when every rational number q with 1 < q < ρ(H) can be realized as the elasticity of some element a ∈ H. Furthermore, we derive results of a similar flavor for locally finitely generated monoids (they include all Krull domains and orders in Dedekind domains satisfying certain algebraic finiteness conditions) and for weakly Krull domains.2010 Mathematics Subject Classification. 13A05, 13F05, 20M13.