1/8" per foot
1/8 th -3/4 in per ft
1/8" per foot
you need to know the PITCH of the drain line to give an proper answer
1/4 inch per foot.
That would depend on PITCH more pitch more fixtures allowed
Most of the time it is 4 inch.
The building code where I live requires a drain pipe to slope approximately 1/4 inch per foot (+ or - 1/8 inch). The recommended pitch for a 50 foot drain would be 12-1/2 inches.
Wouldn't recommend it as things may back up in the drain line. 4" line is the norm ... you want to get rid of waste, not keep it around longer.
The length of a 4-inch line is 4-inches.
Ideally 1/4" per foot minimum
1/4" per foot
The recommended diameter for a 4 inch drain pipe in a residential plumbing system is typically 4 inches.