I need some help calculating water flow and can't find a good calculator/formula to do it. So, hoping some of you might be able to help. Water pressure at spigot is 65psi and 5gpm. Looking to do about 750' of garden hose - 3/8, 1/2, or 5/8 whichever makes the most sense (assuming 5/8 as it is the largest that allows for the most water flow) up a 10 degree angle to the top of a hill. I am assuming with these numbers, it is likely to be a trickle of water that comes out. However, is there a way to calculate gpm with this?