The measurement of steady and fluctuating forces acting on a body in a flow is one of themain tasks in wind-tunnel experiments. Usually, a multi-component strain gauge force and momentsensor (also known as balance) is used to generate signals which are processed by means of anadequate instrumentation.To design a wind-tunnel balance, the specifications of the load ranges and the available space (for theplacement of the balance inside or outside the model) are required. The main challenge is to conceivethe elastic element of the sensor as a monolithic part with a relative simple geometry and to identifythe adequate placement of strain gauges to maximize the measuring sensitivities and to diminish theinter-influence of the components.This paper describes the design of a six-component force/moment sensor which is compact, has highmeasuring sensitivities, and can be used either as internal or as external balance in the aerodynamictesting.