Can someone please help estimate my Total Resistance to Flow (Feet of Head), I'm having a hard time with this.

Pool specs:
In-ground 30,000 Liters / 7800 Gallons
Piping diameter: 1.5 inch
Distance from skimmer to pump location: 45 feet Horizontal and 6.5 feet Vertical
Has 1-skimmer and 2-returns in the pool
Sand filter: 17-inch

Any more info needed?