How many concrete blocks for a 24 ft long, 4 ft high wall?
A 24 ft long, 4 ft high wall (96 sq ft) needs 108 standard 8×8×16 blocks — buy 114 with 5% extra — laid in 6 courses, plus about 9 bags of 80 lb mortar mix.
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Your results
8×8×16 blocks needed114
80 lb bags of mortar mix9
Wall area96 sq ft
Courses (rows) high6
Breakdown
Blocks per course: 18 (each block covers 16 in of length)
Courses: 6 (8 in each)
Total: 108 blocks, 114 with waste
Mortar: 9 bags of 80 lb mix
Need cores filled? Grout and rebar quantities depend on the engineering of the wall; retaining and foundation walls need a design that meets local code.
The math
24 × 4 = 96 sq ft × 1.125 = 108 blocks
× 1.05 waste = 114 blocks · ÷ 13 per bag = 9 bags