Concrete Calculator
Work out how much concrete a slab, footing or round column needs, in cubic yards and premix bags.
Concrete needed
1.36 yd³
- Cubic feet
- 36.67 ft³
- Cubic meters
- 1.04 m³
- 80 lb premix bags (≈0.60 ft³ each)
- 62
- 60 lb premix bags (≈0.45 ft³ each)
- 82
Bag yields are typical for premixed concrete; check the yield printed on your brand's bag.
Show the work
Volume of one slab (thickness in inches ÷ 12 = feet)
V = length × width × (thickness ÷ 12)
10 × 10 × (4 ÷ 12) = 33.3333 ft³
Times how many, plus the waste allowance
V × count × (1 + waste ÷ 100)
33.3333 × 1 × (1 + 10 ÷ 100) = 36.6667 ft³
Cubic yards: 27 cubic feet in each
yd³ = ft³ ÷ 27
36.6667 ÷ 27 = 1.36 yd³
How it works
Volume = length × width × thickness (or π × r² × height for a column), plus waste; 1 yd³ = 27 ft³
Questions
- How does the concrete calculator work?
- Volume = length × width × thickness (or π × r² × height for a column), plus waste; 1 yd³ = 27 ft³.
- What do I need to enter?
- Shape, Length, Width, Thickness, Diameter, Height or depth, How many, Extra for waste. Optional fields can be left blank.
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