The answer to that question. like many legal questions, depends on where the toilet stall is since it will be spelled out in the local building code. Building Codes vary from place to place.
-----------------
Added: The only FEDERALLY mandated regulation governing this might be contained in the Americans With Disabilities Act (ADA) which would only set the minimum width for doors leading to HANDICAPPED rest-room stalls.
the width required for building code space is a minimum of 30 inches.
30" wide X 60" long.
The width of a toilet tank can vary in size. The average width of a toilet tank is about 18 inches.
8' is the legal width of a diveway in nyc
A shower stall should be a comfortable size for the average person. Practical minimum is 36 inches x 30 inches without a door. Anyone taller than 6 feet would probably not be comfortable with a smaller stall. Toilet stalls for public use in the USA are usually governed by the International Plumbing Code. Section 405.3.1 of that code (2006 edition) requires that toilet stalls not be smaller than 30 inches wide by 60 inches long. Distance between the front of the toilet fixture and the door of the stall must be at least 21 inches. Residential requirements are essentially similar. Accessibility regulations typically set the minimum size for stalls serving people with disabilities. The Americans with Disabilities Act of 1990 sets the minimum size for a wheelchair accessible toilet stall at 60 inches wide and 59 inches long, with the toilet fixture set in the corner of the stall opposite the door. The length can be reduced to 56 inches if a wall-hung toilet fixture is used. A minimum size accessible shower stall is 36 inches by 36 inches.
18 inches
Measure the length and width of the floor in the stall. Multiply (length) x (width). If you measured them in feet, then that's your answer. If you measured them in inches, then divide by 144, and that's your answer.
minimum width is like 10 cm and length is like 20 cm
The center of the drain needs to be 12 inches from the back wall and the width is up to you. I would say 30 inches would be the minimum width and that would be tight. How wide are your shoulders side to side ? Most are at least 2 foot or more.
36"
Use a ruler.
Malaysia minimum lane width is 2.75 meter according to JKR U2 and this width only applicable for local streets lane they have pavement roads.