There are multiple sources for how much TNT equivalence you can get from a rocket explosion. I’ll be listing these sources here:
Lunar Expedition Plan - LUNEX - May 1961, Headquarters Space Systems Division, Air Force Systems Command, Page 8.8:
The TNT equivalent of vehicle propellents was estimated in the following manner. The TNT equivalent of the liquid propellents was taken at 60% of the total LOX/LH2 load for all stages. This is the figure currently used at AMR for TNT equivalence for LOX/LH2. In this case, because of the great quantities of propellant involved, this degree of mixing is unlikely and the 60% figure would be conservative.
Solid propellants are taken at 100% of the propellant weight. It is also considered that detonation of the solid propellants may cause the subsequent detonation of liquid propellants and vice versa; but, the simultaneous detonation of all propellants is not likely to occur. This philosophy resolves to consideration of TNT equivalents of liquid propellants and solid propellants separately and they are not additive.