Direct entry of solar radiation through glass in windows plays an important role in increasing the cooling load of air-conditioned building. A number of external and internal shading devices are available (Sharma, 1972) to reduce the heat gain inside the building. Proper design of shading is very important. A simple method has been developed to design the external shading of windows. This method has been discussed in this paper in detail. With the help of curves, designers and architects can find out the dimensions of external shading devices in any orientation.