We give upper and lower bounds on the largest singular value of a matrix using analogues to walks in graphs. For nonnegative matrices these bounds are asymptotically tight. In particular, the following result improves a bound due to Schur. If A = (aij) is an m n complex matrix, its largest singular value satis
es 2 (A) max i2[m] P j2[n] jaij j cj max aij 6=0 ricj ; where ri = P k2[n] jaikj ; cj...