Measure from the center of the door knob hole to the edge of the doorway to find the size of the door set.
Standard door handle dimensions.
Then you need to measure the width most common width are 2 6.
According to international building code 2012 door handles or knobs should be installed 34 inches 864 mm minimum and 48 inches 1219 mm maximum above the finished floor.
Standard interior slab doors are 80 inches tall.
The standard door thickness is 1 inches.
Installation at 40 inches is common on affordable homes mobile homes and production homes.
The standard size for an exterior door is 80 inches 6 feet 8 inches by 36 inches 3 feet.
Some door manufacturers carry stock doors in 7 foot and 8 foot heights and door widths from 24 inches to 42 inches.
There are some international rules of where you should place your door handle or knob.
Stock exterior doors are also commonly available in 30 inch and 32 inch widths.
Next you need to determine which direction the door opens in out left right swings.
If you re installing several doors it s acceptable to drill the doorknob hole at 40 inches or centered vertically.
In most cases the door set which is inside of the door and controls the door latch will.
General requirements for access recommends that the height of the handle should fall within 900mm and 1100mm above the floor.