I should, first of all, state that I have very limited knowledge of physics but as a fitness enthusiast the following question has puzzled me for a while. When I do squats on the gym holding a kettlebell (say 30kg) close to my chest I guess the weight is exactly on my center of mass. However, when I lift the same weight using a barbell I feel like it is much easier to lift probably because the weight, in the case of the barbell, is distributed evenly across the iron bar [assume an iron bar weighting 30 kg with no added weight].

So I was wondering if there is an equation that can be used to calculate how much weight I need to increase the barbell squats in order to feel like the kettlebell squats if that makes any sense ? e.g. if I can do 30kg squats with the weight on my center of mass, how heavy needs the weight to be when it is distributed evenly (barbell) in order to do the same Work (I guess that's what you call it in Physics ?).

Sorry, if this question is stupid and consider my complete lack of knowledge of physics :)