The length of a cowl required to wrap twice around your neck depends on several factors, including the circumference of your neck, the desired snugness of the fit, and the thickness of the yarn or fabric used to make the cowl. As a general rule of thumb, a cowl that is approximately 60-70 inches (152-178 cm) long would be long enough to wrap twice around an average adult's neck. However, it's always a good idea to measure your neck's circumference and try on the cowl as you work to make sure that you achieve the desired fit.