There really does not... it depends on the type and size of the toilet, but as a rule of thumb that size covers most toilets, and is a comfortable distance to work for most situations.
Depends on the toilet being purchased, but generally 12 inches from the wall to the center of the toilet flange for a residential toilet.
you pee in the shower?
The drains for the shower, toilet and sink all connect to a common line. Assuming the toilet is not backing up, the problem indicates that there may be a partial blockage, enough so that some of the toilet flow is backing up through the shower drain line. You need plumbing repair. The shower leak you mention should only be in the shower, or else you have a broken drain line as well.
The drain from the toilet to the main drain is plugged and the branch to the shower is not. If the main floor toilet flushes, it is between the two toilets and not between the house and the sewer.
You need at least a 3 in. pipe -- shower is 2 in. pipe
18 inches to center
30 inches.
The minimum distance is 15 inches from the center of the closet shoe or toilet to the edge of the lav or vanity.
a tiolet needs a minimum of 15 inches from center to either side
12 inches from the center of the drain to the back wall behind the tank. Some toilets are 10" rough in. Also should be 18" from side wall to center of toilet if possible.
Installing a toilet is not an easy, do-it-yourself task. It takes skill and precision to complete all the steps necessary. This is possibly the single, most troublesome fixture to install as it requires its own 2" minimum vent and a drain of at least 3" in diameter. If the toilet is situated on a branch drain, it cannot be upstream from the sink or shower. The minimum side distance allowed from the center of the toilet bowl to a wall is 15 inches, and 12 inches from the center of the bowl to a bathtub; clearance from the front of a bowl to a wall or fixture should be 21 inches. You can find further do-it-yourself instructions from a local hardware store that sells plumbing equipment.
The 2003 International Plumbing Code calls for a minimum of 15" clearance from the center of the water closet (toilet) to the nearest side wall or other fixture and 21" clearance from the front of the bowl to the closest wall or fixture.
Code minimum 15" to center of toilet from side wall.
The minimum distance required is 15" either side/ that is minimum.
15 inches from outside edge of tub to center of toilet flange.
5 3/4 inches
Would be risking damage to the tank and possibly open for a major lawsuit