Not sure if this is quantifiable, really, but we can get a range based on real world sources.
His explosion is larger than the one caused by this 200 gram nitroglycerin explosion, but smaller than the one caused by this 375 gram nitroglycerin explosion. Considering the energy density of nitroglyercin, this would put his explosion between 1,280,000 and 2,390,000 J. Or about 1 to 2/5ths the energy of a tank round for reference. In either case, this feat would be Wall Busting.
As I said, not sure this is really calcable, but if you want it on a blog for future reference I can do that.