The bags-per-hundred rule
Mortar estimating has a dependable rule of thumb: <strong>one 80-lb bag of mortar lays about 33 concrete blocks or 150 bricks</strong>, with roughly a quarter cubic yard of sand per bag. The calculator scales that to your count — round up, because a half-batch that dries out mid-wall is wasted either way.
Type S or Type N?
Type S mortar (higher strength) is standard below grade, for retaining walls and any load-bearing CMU work. Type N is softer and better for above-grade brick veneer repair. The bag count barely differs — the choice is about what the wall does, not how much material it takes.