Paint Calculator
Plan paint quantities from area, coverage, and coats.
Home & Projects · FREE TO USE
Concrete Calculator
Estimate volume and bag count for a rectangular slab.
02EXAMPLE RESULT
Concrete to order
2.2
m³
Slab volume before allowance2m³
Volume in cubic yards2.877491yd³
Estimated bags110bags
Total mixed volume2,200L
Results update as you type. Calculate adds a snapshot to your history.
How this calculation works
Calculate a rectangular slab’s volume and add your chosen allowance. Bag counts use the product’s mixed yield, not its dry weight.
Volume (m³) = length × width × (thickness ÷ 100) × (1 + allowance ÷ 100)
Your calculation, step by step
- Slab volume = 5 × 4 × (10 ÷ 100) = 2 m³.
- With 10% allowance = 2.2 m³.
- Bags = ceiling(2,200 ÷ 20) = 110.
A worked example
A 5m × 4m × 10cm slab needs 2.2m³ including a 10% allowance.