Is one cc of fat equal to one syringe of filler in volume?

Technically, yes. One cc of fat is equivalent to one cc of filler. The difference is that some of the fat (usually around 30% when larger volumes are injected) is absorbed over time postoperatively.
Dr. Taranow

When grafting fat the injected particles always contain a certain percentage of water. The amount of water depends on how the fat is processed during harvest and in preparation for grafting. after grafted a certain percentage of fat when not survive. A typical response to how much fat survives is about 50% but this varies substantially on a multitude of variables.

Grafted fat should not be compared to fillers in a volume ratio. They are like comparing apples and oranges or cats and dogs.

They’re completely different.

A full face fat transfer procedure may require 30 to 50 mL a fat.

That amount of filler is virtually unheard of.

For facial work fillers are far more predictable consistent and forgiving and is typically the way to go.

Best,

Mats Hagstrom MD