Let W be a vector space of dimension n + 1 over a field K. The Chow divisor of a k-dimensional variety X in P n = P(W ) is the hypersurface, in the Grassmannian G k+1 of planes of codimension k + 1 in P n , whose points (over the algebraic closure of K) are the planes that meet X. The Chow form of X is the defining equation of the Chow divisor. For example, the resultant of k + 1 forms of degree e in k + 1 variables is the Chow form of P k embedded by the e-th Veronese mapping in P n with n = k+e kIn this paper we will give a new expression for the Chow divisor and apply it to give explicit formulas in many new cases. Starting with a sheaf F on P n , we use exterior algebra methods to define a canonical and effectively computable Chow complex of F on each Grassmannian of planes in P n . If F has k-dimensional support, we show that the Chow form of F is the determinant of the Chow complex of F on the Grassmannian of planes of codimension k + 1. The Beilinson monad of F [Beilinson 1978] is the Chow complex of F on the Grassmannian of 0-planes (that is, on P n itself.) In particular, we are able to give explicit determinantal and Pfaffian formulas for resultants in some cases where no polynomial formulas were known. For example, the Horrocks-Mumford bundle gives rise to polynomial formulas for the resultant of five homogeneous forms of degrees 4, 6 or 8 in five variables. The easiest of our new formulas to write down is for the resultant of 3 quadratic forms in three variables, the Chow form of the Veronese surface in P 5 . Using the tangent bundle of P 2 , conclude that it can be written in "Bézout form" (described below) as the Pfaffian of the matrix