Retaining Wall Block Calculator
Plan your retaining wall project accurately. Enter the wall length and height along with your block dimensions to get the total number of blocks, cap stones, base gravel, and drainage backfill estimates.
Wall & Block Dimensions
Full Breakdown
Wall Face Area
Rows (Courses)
Blocks per Row
Wall Blocks (with waste)
Cap Blocks
Base Gravel (tons)
Drainage Backfill (cu yd)
Estimated Block Cost
How to Use This Calculator
- Enter the total wall length in feet.
- Enter the desired wall height in feet.
- Set the block dimensions (default: 12″ long × 4″ tall, common landscape block).
- Optionally enter a price per block for cost estimates.
- Click "Calculate Blocks" for a full material breakdown.
The Formula
Rows = ⌈(Wall Height × 12) ÷ Block Height⌉
Blocks per Row = ⌈(Wall Length × 12) ÷ Block Length⌉
Total Blocks = Rows × Blocks per Row × (1 + Waste%)
Cap Blocks = Blocks per Row
Base Gravel = Wall Length × 2 ft wide × 6 in deep (at 1.4 t/cu yd)
Backfill = Wall Length × 1 ft wide × Wall Height (cu yd)
Blocks per Row = ⌈(Wall Length × 12) ÷ Block Length⌉
Total Blocks = Rows × Blocks per Row × (1 + Waste%)
Cap Blocks = Blocks per Row
Base Gravel = Wall Length × 2 ft wide × 6 in deep (at 1.4 t/cu yd)
Backfill = Wall Length × 1 ft wide × Wall Height (cu yd)
Base gravel assumes a 2 ft wide × 6 in deep compacted base. Drainage backfill assumes 1 ft of crushed stone behind the wall. Adjust for your design.