Multi-constraint quality-of-service (QoS) routing has become increasingly important as the Internet evolves to support real-time services. It is well known, however, that optimum multi-constraint QoS routing is computationally complex, and for this reason various heuristics have been proposed for routing in practical situations. Among these methods, those that use a single mixed metric are the most popular. Although mixed metric routing discards potentially useful information, this is compensated for by significant complexity reduction. Exploiting this tradeoff is becoming increasingly important where low complexity designs are desired, such as in battery operated wireless applications. In this paper, novel single mixed metrics for multi-constraint routing are introduced. The proposed techniques have similar complexity compared with existing low complexity methods. Simulation and analytical results are presented which show that it can obtain better performance than comparable techniques in terms of generating feasible routes.