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Concrete Slab Estimate Calculator
Estimate rectangular slab volume and optional bulk or product-specific bagged concrete cost.
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01 / EnterThese are editable examples, not recommended rates. Enter your own numbers.
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Show the math
Estimates use unrounded numbers. Displayed amounts round to cents.
What this means
The calculation estimates concrete material for a simple rectangular slab. Bagged and bulk costs are separate purchasing alternatives.
Worked example
A 12 ft × 9 ft slab at 4 in thickness is 36 ft³ or 1.333333333 yd³. At 10% overage it needs 39.6 ft³. A user-supplied 0.6 ft³/bag yield requires 66 bags.
How the math works
Cubic feet = length(ft) × width(ft) × thickness(in) / 12. Cubic yards = cubic feet / 27. Add overage multiplicatively. Bags = ceiling(adjusted cubic feet / product yield).
About this estimate
Uniform depth; no reinforcement, excavation, structural sizing, delivery fees or tax. Yield and prices must come from the actual product or supplier. Zero slab volume gives zero material quantity.
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Formula v1.0.0 · Reviewed · Tool ID: concrete-slab