Classes of nuclear weapons:
Battlefield – bunker busters, tank squadron killers etc.
Tactical (one that lands in Germany and before anyone rants that’s from a German)
Strategic – city killers, actually MIRV warheads are used to carpet bomb the area rather than one big bang.
Backyard (courtesy of Edward Teller father of the H-Bomb, one that’s so big it doesn’t matter where you detonate it there’s nothing left).
Actually there is no point going over 50MT as any larger just tends to lift a chunk of atmosphere up rather than going any further outwards.