Masonry
Concrete Block Calculator
Calculate the number of concrete blocks needed for walls, foundations, and structures. This calculator estimates both the number of blocks and the mortar required for your project.
Enter Your Measurements
Formula Used
Blocks = (Length × 12 ÷ 16) × (Height × 12 ÷ 8) Add 5-10% for waste and cuts
Pro Tips
- •Order 5-10% extra blocks for waste and cuts
- •Standard blocks are 8" high × 16" long (actual size slightly less)
- •Use type S mortar for below-grade applications
- •Consider insulation-filled blocks for energy efficiency
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Frequently Asked Questions
How many concrete blocks do I need per square foot?
For standard 8x8x16 blocks, you need approximately 1.125 blocks per square foot of wall area.
How much mortar do I need for concrete blocks?
You need about 3 bags of mortar per 100 blocks. Each bag of mortar covers approximately 30-35 blocks.