We study the power of deep neural networks (DNNs) with sigmoid activation function. Recently, it was shown that DNNs approximate any d-dimensional, smooth function on a compact set with a rate of order W−p/d, where W is the number of nonzero weights in the network and p is the smoothness of the function. Unfortunately, these rates only hold for a special class of sparsely connected DNNs. We ask ourselves if we can show the same approximation rate for a simpler and more general class, i.e., DNNs which are only deﬁned by its width and depth. In this article we show that DNNs with ﬁxed depth and a width of order Md achieve an approximation rate of M−2p. As a conclusion we quantitatively characterize the approximation power of DNNs in terms of the overall weights W0in the network and show an approximation rate of W−p/d0. This more generalresult ﬁnally helps us to understand which network topology guarantees a special target accuracy.