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Retaining Wall Materials for a 20' × 3' Wall

A 20-foot wall 3 ft high is 60 sq ft of face — about 90 standard 16×6" blocks plus caps and base gravel. Pick a different block size, a custom block, or poured/timber/stone above.

You'll need
90 blocks
Wall area
60 sq ft20' long × 3' high
Wall blocks
9016" long × 6" high × 10" deep
Cap blocks
15~16" units
Gravel base / backfill
1.0 tons6"-deep leveling base + drainage backfill
Block cost (est.)
$450~$5/block material
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