Since yield will vary depending on the facility and your skills, I would drop a load of ore into the reprocessing hopper at your facility of choice and see the actual yield - at that point you can use Google sheets or Excel to do the math.
Personally, I buy minerals. A DST with giant secure containers can haul a decent load but I tend to make small stuff like modules and drones - you’ll need freighter loads if you’re building battleships and compressed ore is more space efficient.