That's a really difficult question because the Husafell is so different to a barbell - along with the fact you have to carry it 35m. There are aspects of grip and wingspan involved, too.

I say this as someone who hasn't touched the Husafell in Iceland (yet), so take it with a pinch of salt: From what I've seen, if you haven't hit a ~200kg (440 lb) squat and a ~250kg (550 lb) deadlift, you might struggle with the Husafell stone.