How to use this calculator
- Enter wall length and height. In feet. For multi-section walls, calculate each section separately and sum.
- Pick the block size. Standard 8×8×16 hollow is the residential default. Use 6×8×16 for non-load-bearing partitions, 12×8×16 for retaining walls, 4×8×16 for veneer or thin walls.
- Set waste percentage. 5% for straight walls. 10% for corners, T-intersections, and openings.
- Override price (optional). Enter your local price if it differs from the 2026 retail default ($1.45–$3.25 depending on size and type).
Formula
Blocks = Wall Area × 1.125 × (1 + Waste %); Pallets = Blocks ÷ Pallet Capacity
Worked example
A 20 × 8 ft wall (160 ft²) using 8×8×16 hollow blocks at 5% waste: 160 × 1.125 × 1.05 = 189 blocks. That's 3 pallets (90 blocks each), 6,237 lb total weight, 7 bags of mortar. At $1.85/block: $350 in materials, plus $63 in mortar.
Common project sizes
Quick reference for the most common cinder block calculator use cases. Use these as a sanity check on your calculator inputs.
| Project | Dimensions | Result |
|---|---|---|
| Garden wall (20 × 4 ft) | 80 ft² | 95 blocks · 2 pallets · 3,135 lb · 4 mortar bags |
| Garage wall (20 × 8 ft) | 160 ft² | 189 blocks · 3 pallets · 6,237 lb · 7 mortar bags |
| Foundation (40 × 4 ft) | 160 ft² | 189 blocks · 3 pallets · 6,237 lb · 7 mortar bags |
| Basement walls (120 × 8 ft) | 960 ft² | 1,134 blocks · 13 pallets · 37,422 lb · 38 mortar bags |
| Retaining wall (50 × 4 ft, 12-in) | 200 ft² | 236 12×8×16 blocks · 4 pallets · 11,800 lb · 8 mortar bags |
2026 cost reference
Typical retail price range in the United States for cinder block. Local pricing varies by region, supplier, and grade — confirm with two or three quotes before ordering.
Per pallet (90 blocks 8×8×16 hollow)
$115 – $225
2026 U.S. retail. Trade pricing 15–25% lower with bulk orders (3+ pallets). Add $50–$150 delivery for residential. Decorative, split-face, and architectural blocks: $200–$400 per pallet.
Tips for accurate results
- A standard 8×8×16 hollow cinder block weighs ~33 lb. Solid blocks weigh ~50 lb. Half blocks (4×8×16) weigh ~18 lb.
- Pallets vary by supplier. Counts of 70-90 are most common for 8×8×16 hollow; some suppliers go up to 120 for tighter stacking.
- Mortar: 1 bag (70 lb) lays approximately 30 standard blocks at 3/8" mortar joints. Add 1 extra bag per 100 blocks for waste.
- Cinder block, concrete block, and CMU (Concrete Masonry Unit) refer to the same product. "Cinder" technically means it contains coal cinders — modern blocks are concrete with lightweight aggregate.
- Always order from a single batch when possible. Color and surface texture vary slightly between manufacturing runs.
When to consult a pro
Cinder block wall construction is a skilled trade — getting plumb walls and consistent mortar joints takes practice. For garden walls under 4 ft tall, DIY is workable with a string line and a mason's level. Anything load-bearing, structural, or above 4 ft: hire a mason. The hidden costs of bad block work (cracks, plumbness errors, water infiltration) far exceed the savings.