I believe the general rule is 20 points for specialty grain and 28 points for base grain. 35 points for liquid malt extract and 42 for dme.
This per pound per gallon. So if you use 1/2 pound of Pale Chocolate for 5 gallons, that would be 10 points divided by 5 gallons so it would give 2 points on the hydrometer.
Let me know if you don't follow and I can explain further.
Forrest