How thick are most standard interior doors?

Most standard interior doors are typically 1-3/8 inches thick. This thickness is a common industry standard, providing a balance of durability, insulation, and fit within standard framing dimensions for interior applications. The 1-3/8 inch thickness allows for adequate soundproofing and supports the structural integrity of the door, which is important for day-to-day use in homes.

Doors that are 1 inch thick are more common in specific applications like lightweight or economy doors and do not provide the same level of durability. A thickness of 1-1/2 inches is often used for exterior doors or high-performance doors that require extra strength or insulation. Finally, 3/4 inch doors are typically found in specialized applications, such as cabinet doors or other lightweight structures, and are not standard for general interior doors. Thus, 1-3/8 inches stands out as the conventional choice for residential interior doors.