Over 5 million copies were sold in one week.
God of War Ragnarok screenshot

Sony announces that God of War Ragnarök is the fastest selling first-party PlayStation title ever. This means that Ragnarök bested releases for The Last of Us, Uncharted, Horizon, and even Knack.

Revealed in a tweet, Sony says that God of War Ragnarök sold 5.1 million copies in its opening week. Though it need not be stated, Sony also notes that this milestone set a God of War franchise record as well.

The sales figure shared does seem to indicated the combined sales on PlayStation 4 and PlayStation 5. This is one area where God of War Ragnarök has a leg up on the other first party competition as most of those games had long stretches of time between their initial release and next-gen release.

For the sake of generic comparisons here, 2018's God of War sold 23 million copies on PlayStation 4 and PC as of November 2022. It does not seem unreasonable to expect God of War Ragnarök to also appear on PC at some point, but it probably won't be until late 2023 at the absolute earliest.