supply line sizing

[apparentgenius]

Hi,

I am in the process of plumbing a new house with PEX. I have a 1" main coming into the house.

Is there a limit of how many 1/2" fixture supply lines that I can take off of a a 3/4" branch off of the main? My total fixture units on the second floor is 23 made up of 4 sinks,2 toilets, 1 tub, 2 shower heads 1 washer, 1 dishwasher.
The distance from the 1" supply line to the furthest fixture is about 30'

Any help is appreciated.

glen

http://www.terrylove.com/watersize.htm