The amount of gap between a watch and the wrist is largely dependent on personal preference. Generally, a gap of 1/4 to 1/2 inch is considered ideal for most watches. This allows enough room for air circulation around the watch and prevents any discomfort or pinching that can occur when the watch is too tight against the skin. It also helps keep dirt and debris from entering into the mechanism of the watch, which can cause it to malfunction over time. Ultimately, finding an optimal fit should be based on comfort as well as aesthetics.