Concrete Slab Calculator

Determine how much concrete you need for your slab project. Enter length, width, and thickness to get cubic yards, number of bags (60lb and 80lb), and total cost including optional reinforcement (wire mesh or rebar).

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Recommended: 5-10%
Average: $125-175

Concrete Estimate

Concrete Needed
5.43
cubic yards
Total Cost
$975
estimated
326
60 lb bags
$2,119
245
80 lb bags
$1,838
Area
400 sqft
Volume
133.3 cuft
Before Waste
4.94 yd
Waste
+10%

How to Use Concrete Slab Calculator

  1. 1Enter slab length, width, and thickness
  2. 2Set waste factor (5-10% recommended)
  3. 3Choose reinforcement type
  4. 4View cubic yards, bags needed, and total cost

Frequently Asked Questions

How many bags of concrete do I need?

An 80lb bag covers about 0.6 cubic feet (0.022 cubic yards). For a 10x10ft slab at 4 inches thick, you need about 1.23 cubic yards or approximately 56 bags of 80lb concrete. Always add 5-10% for waste.

How thick should a concrete slab be?

Sidewalks and patios: 4 inches. Driveways for cars: 4-5 inches. Driveways for trucks: 5-6 inches. Garage floors: 4-6 inches. Commercial floors: 6-8 inches.

How much does ready-mix concrete cost?

Ready-mix concrete costs $125-175 per cubic yard delivered. For small projects under 1 cubic yard, bags may be more economical at $6.50-7.50 per bag.

About Concrete Slab Calculator

Determine how much concrete you need for your slab project. Enter length, width, and thickness to get cubic yards, number of bags (60lb and 80lb), and total cost including optional reinforcement (wire mesh or rebar).

NexTool's Concrete Slab Calculator is completely free to use with no sign-up required. Your data is processed directly in your browser and never sent to our servers, ensuring complete privacy and instant results.

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