Accurate material estimation is the difference between a smooth project and an expensive disaster. Under-ordering means delays and rush delivery charges. Over-ordering wastes money and creates disposal problems. This guide covers the core formulas for the three most common construction materials.
Step 1: Concrete Volume
Volume (yd³) = (Length × Width × Depth in feet) / 27 27 cubic feet = 1 cubic yard. Always convert depth from inches to feet first (divide by 12).
Example: A 20×20 ft patio, 4 inches thick: (20 × 20 × 0.333) / 27 = 4.94 yd³. With 10% waste: 5.43 yd³ — order 5.5 yards. Use the Concrete Calculator for complex shapes.
Step 2: Brick Estimation
| Brick Type | Per Sq Ft (wall) | Per 100 Sq Ft |
|---|---|---|
| Standard Modular (3∕8×2⅜×7∕8) | 6.75 | 675 + mortar |
| King Size | 4.5 | 450 + mortar |
| Queen Size | 5.76 | 576 + mortar |
Add 5-10% waste for cuts and breakage. Use the Brick Calculator for bond pattern adjustments.
Step 3: Lumber Board Feet
Lumber is measured in board feet: one board foot = 12×12×1 inches. For framing, add 15% waste for cuts, and 20% for decking due to angled cuts and knot culling.
Calculate concrete, brick, and rebar for any project shape
Try the Concrete Calculator →Key Takeaways
- Always add waste factors: 10% for concrete, 5-10% for brick, 15-20% for lumber.
- Concrete: divide cubic feet by 27 to convert to cubic yards for ordering.
- Standard modular brick: ~7 per sq ft of wall surface including mortar joints.
- Order slightly over — the cost of a short order far exceeds the cost of extra material.