In America, the most common thickness for cabinet doors is typically 3/4 inch (0.75 inches or approximately 19 mm). This thickness provides sufficient strength and stability for cabinet doors while maintaining a standard look. However, it's important to note that cabinet door thickness can vary depending on the manufacturer, style, and specific design preferences. Some custom or high-end cabinets may have thicker doors, typically ranging from 7/8 inch to 1 inch (22 mm to 25 mm). It's always a good idea to consult with the cabinet supplier or manufacturer to determine the exact thickness options available for the specific cabinets you are considering.