Enter your Wall Width, Wall Height, and Block Width and Block Height to calculate exactly how many Standard Blocks you'll need — plus Cap Blocks, Base Gravel, Backfill Gravel, and an Estimated Total Cost once you add your Block Price, Cap Block Price, and Base Gravel Price.
Total Standard Blocks Needed
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Cap Blocks Needed
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Base Gravel
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Backfill Gravel
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Estimated Total Cost
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Calculate the number of rows by dividing wall height by block height, and the number of columns by dividing wall width by block width. Multiply rows by columns to get the total number of blocks needed.
Backfill gravel provides proper drainage behind the retaining wall, preventing water buildup that could cause pressure and potential wall failure. It should extend from the base to about 6 inches below the top of the wall.
Base gravel should be 6 inches deep and extend 6 inches beyond both sides of the wall. Calculate the volume as: (wall width + 1 foot) × 0.5 feet × wall depth, then convert to cubic yards.
Cap blocks are recommended for the top row as they provide a finished appearance and better structural integrity. They're typically wider than standard blocks and help distribute weight evenly.
The foundation depth should be approximately 10% of the wall height, with a minimum of 6 inches. For taller walls over 4 feet, consider consulting a structural engineer for proper foundation requirements.
Main cost factors include block type and quality, wall height and length, site preparation requirements, drainage needs, and local labor costs. Additional features like lighting or curves will increase costs.
Walls under 4 feet high can often be DIY projects with proper planning and materials. Taller walls or those holding back significant soil loads should be designed and built by professionals to ensure safety and compliance with local codes.