In this talk, we give localise the spectrum of a discrete magnetic Laplacian on a finite graph using techniques similar to the Dirichlet-Neumann-bracketing for continuous problems. As application we localise the spectrum of periodic Laplacians using the fact that the fibre operators from Floquet Bloch theory can be seen as magnetic Laplacians. Finally, we use the bracketing ideas to order spectra of different graphs, and show how certain graph manipulations change the spectrum.