Single-material calculator

Concrete Calculator

Concrete volume estimates for slabs, continuous footings, and post holes with waste built in.

Quick presets

Start from a typical North American scenario, then tune the job-specific inputs.

Inputs

Pour type

Pour Type Switch between slab-on-grade, continuous footing, cylindrical post-hole, or above-grade sonotube pier planning.

Concrete procurement

Concrete Procurement Choose one purchasing path. Bagged mix is shopping-oriented; ready-mix is shown as quote-first cubic yards and does not use bag SKU pricing. Bag Size Smaller bags are easier to carry and hand-mix; the same volume just needs more of them (80 lb ≈ 0.60 cu ft, 60 lb ≈ 0.45, 40 lb ≈ 0.30).

Slab geometry

Slab Length (ft) Type it the way you measured it - 16' 6" or 16.5 both work. Slab Width (ft) Slab Thickness (in) Four inches is a common residential flatwork baseline; heavier loads often need a thicker section or engineered design.

Slab scope

Slab Reinforcement 6x6 means a 6-inch grid. Adds a basic reinforcement allowance for common residential flatwork.

Include 6 mil vapor barrier Use this when the slab needs a basic moisture break under conditioned interior spaces or finish flooring.

Footing geometry

Post holes

Sonotube piers

Advanced settings

Waste Factor (%) The calculator shows cubic yards and bag equivalents from the same volume, so the bag count is a convenience conversion rather than a second design method.

Regional settings

State / Pricing Region Selecting a state adjusts material prices by a state-level cost index, not by store listings in your city. States without an index keep the national baseline, and the estimate says so.

Reset inputs

Use this button to recalculate without JavaScript or create a complete, shareable page URL.

2D plan

Schematic quantity basis

2D and 3D previews are schematic. Drag to orbit, and scroll or pinch to zoom when 3D is open.

3D assembly

Optional 3D check

3D is optional here. Use it to sanity-check the base profile after the 2D quantity path is clear.

Slab area 64 sq ft

Adjusted volume 0.83 cu yd

Waste factor 5 %

Reinforcement 6x6 welded wire mesh

Reinforcement rolls 1

80 lb bags 38

Plan details & review

Planning assumptions

Included scope: Slab, Footing, Post holes.

Planning assumptions · 5

Volume assumes a uniform slab thickness with no thickened edges or interior haunches.
Bag conversion uses 80 lb concrete bags as a planning equivalent.
Verify subgrade prep, reinforcement, control joints, and local code before ordering.
Reinforcement allowance assumes a basic welded-wire mesh layout only and is not a substitute for structural or jurisdiction-specific slab steel design.
The BOM rounds packaged materials to whole purchase units such as gallons, bags, boxes, buckets, rolls, cartons, tubes, jars, bundles, or kits, so bought quantity can exceed the exact theoretical coverage shown by the area metrics.

Not included / Trade review

2 total scope notes to read before ordering or contractor handoff.

How pricing works

Schematic slab quantity only. Base prep, joints, and structural detailing stay outside this calculator; optional mesh and vapor-barrier allowances are planning-level only.

Material estimate for the quantities in this plan.

Need local install pricing?

Save this estimate to reopen it later, share the link or the plain-text takeoff, or export a PDF. Pin to compare stacks alternate inputs side by side.

Compare contractor quotes

Material list

Your build list

Each line shows a purchase quantity, a coverage amount, or a planning allowance - the line says which. Check pack sizes and your site conditions before you order.

Material	Assembly	Unit	Qty	Unit price	Total	Source
80 lb concrete bags Calculator default	slab	bag	38	$4.58	$174.04	Home Depot Shopping-ready Price source: Retailer pricePrice as of: 06/01/2026 — price may have changed - verify before orderingRetailer: Home Depot
Quantity basis The visible row quantity is a purchase or ordering quantity. Qty: 38 Quantity type: Purchase quantity Purchase quantity: 38 Coverage: Waste-adjusted slab volume Waste factor: 5%
6x6 welded wire mesh Calculator default	slab reinforcement	roll	1	$159.00	$159.00	Home Depot Shopping-ready Price source: Retailer pricePrice as of: 06/05/2026 — price may have changed - verify before orderingRetailer: Home Depot
Quantity basis The visible row quantity is a purchase or ordering quantity. Qty: 1 Quantity type: Purchase quantity Purchase quantity: 1 Coverage: Slab area with lap allowance Waste factor: 5%

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Estimated materials total$333.04

Material guide

Concrete quantity and procurement guide

Switch between tabs to see how this calculator works and what stays outside its scope.

Volume first, procurement second

Slab: Length x width x thickness, converted from cubic feet to cubic yards, then waste-adjusted.
Footing: Linear run x footing width x footing depth, with width and depth entered in inches.
Post holes: Cylindrical hole volume x count. Post displacement, bell footings, uplift design, and frost-depth compliance are not modeled.

This calculator is a planning takeoff. It is not a permit-ready slab, footing, or structural concrete design.

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Current takeoff: 0.83 cubic yards of slab concrete.

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