In this paper we present an approximate closed form solution for dimensioning mixed service 3G wireless networks for defined service and quality constraints. Both web-browsing services alone, as well as a mixture of web and circuit voice services are considered. Dimensioning is achieved through knowledge of the distribution of the latency delay experienced by end users of the 3G network. The parameters defining the distribution are shown to be dependent on a range of network and service parameters. This allows the dimensioning of 3G wireless networks under a wide range of quality and service conditions.