According to BYO malt absorbs roughly 1.04L of water per kg malt. Knowing this makes calculating things like mash and sparge water quite a bit easier.
Is there a rough absorption rate for hops?
I've searched round the web but cannot seem to find anything. I guess it may vary according to the hop size and density, but some rough figures will help with calculations like topping up water and rackable post-fermentation volume.
Is there a difference between adding hops in the boil vs dry hop?