What is the thickness of a standard internal door?
Standard thickness for an interior door is 1 3/8, if your door exceeds 36” or is over 90” in height; the recommended thickness for that door would be 1 3/4 inches. The chart below has a list of widths and heights and what those sizes are generally used for.
What is the thickness of most residential interior doors?
1 ¾ inch
How thick is a solid wood door?
The standard is 80" tall 36" wide and 1 5/16" thick. If you use a stable wood, quarter-sawn, you won't have problems with movement. Most interior doors are thinner than exterior. It adds about 25% to your material costs by going 1/2" thicker, and then you need the cutters to produce the thicker doors.