it depends on what size of bales your making a 4x4 bale i would say you would want 60 hp, for bigger bales like 5 x6 you would want 70 to 100 hp. Everything will work better with More horse power. I do small squares with my dad with an allis chalmers d15, about 45 hp. It runs good and we dont have tons of issues, but big round bales are a whole different animal. I really wouldnt feel comfortable running one till 65 to 70 horse. Weight goes up incrementally typically as you get more hp tractor. One thing to note, is I have never heard anyone say they wish they had less tractor, it is usually the other way around.
