Depends on if you purge the oil out of the oil cooler. If the engine's been laid up for several years, you may want to do this.
The 13-row oil cooler I have might hold 1/2 qyuart, give or take.
Since my car has a remote spin-on filter (hanging straight down) I can prefill it with oil too, minimizing the time it takes to obtain oil pressure upon startup.