No I can't. It will be slightly more than a cup due to the air spaces between the pellets.. Very much the same as trying to calculate how much wood there in a volume of wood pellets.
I would simply melt the wax to achieve the volume you want, then add the oil. Make sure it is well stirred prior to cooling. If for some reason you find the end product is too soft or too hard, a remelt and the
addition of either wax to make it harder or oil to soften will get what you want. Don't forget to stirr. For hot weather storage (Texas qualifies) you may consider storing the puck in the fridge. Bonnie should
approve, I hope. Hope this helps.