The remainder of this work is organized as follows. Section 2 provides a brief introduction to the formalism of linear-response TD-DFT and also introduces some visualization tools based on the density matrix, which are more incisive than simply plotting ∆ρ(r) in real space. Orbital-based visualization tools, which remain the most popular means for qualitative characterization of an excited state, are introduced in Section 3. To quantify charge rearrangement during excitation, it is useful to introduce an atomic partition of ∆ρ(r) that can be made into a metric for CT but can also assist in understanding states that are delocalized across more than one chromophore. These tools are introduced in Section 4, and then Section 5 introduces additional ways to quantify exciton delocalization that have a direct connection to the underlying wave function or transition density. Finally, the CT problem in TD-DFT calculations is described in Section 6 along with a discussion of various metrics that can be used to indicate when (and for which excited states) this becomes an issue.