Concrete Slab Cost Calculator
This concrete slab cost calculator estimates the cost of a slab on grade from its size, the local concrete price, labor, and reinforcement. Enter the slab dimensions and your rates and the concrete slab cost calculator returns the total cost, the cost per square metre, and a breakdown of concrete, labor, and reinforcement.
Results
The Concrete Slab Cost Calculator is part of our Concrete collection. Browse more concrete to size, convert, and check your work alongside this tool.
What the concrete slab cost calculator shows
A slab's cost comes from three parts: the concrete itself, the labor to form, pour, and finish it, and the reinforcement such as mesh or rebar. The concrete slab cost calculator multiplies each by the slab size using rates you enter, so the estimate reflects your local prices rather than a national average.
Estimate concrete slab cost: the formula
Concrete cost scales with volume, so a thicker slab raises it; labor and reinforcement scale with area.
Concrete slab price calculator example
A 6 m by 4 m slab, 100 mm thick, with concrete at 150 per m³, labor at 25 per m², reinforcement at 5 per m², and 5 percent waste:
Labor is often the largest share, which is why small slabs cost more per square metre.
How to use the concrete pad cost calculator
Enter the slab length, width, and thickness, your concrete price per cubic metre, labor cost per square metre, reinforcement cost per square metre, and a waste allowance. The concrete pad cost calculator returns the total cost, cost per square metre, the concrete volume, and each cost component. Get local quotes for the rates; prices vary widely by region.
Reading the slab cost estimator results
The cost per square metre lets you compare quotes and slab sizes. This estimate covers the slab itself; site preparation, excavation, a gravel base, permits, and finishes such as stamping or coloring are extra. It applies to slabs on grade, such as patios, pads, and garage floors, not suspended structural slabs.
When to use the concrete patio cost calculator
- Budgeting a patio with the concrete patio cost calculator
- Comparing contractor quotes per square metre
- Pricing a shed base or garage pad
- Testing how thickness changes the cost
Common concrete slab cost calculator mistakes
- Using national averages. Enter local rates.
- Forgetting the base and site prep.
- Ignoring short-load fees on small pours.
Tips for accurate results
- Get at least two local quotes for the rates.
- Ask whether labor includes forming and finishing.
- Compare cost per square metre, not just totals.
Concrete slab installation cost calculator: what drives it
Installation cost depends on access, formwork, finishing, and the crew's rate, which is why labor often outweighs material on small jobs. A pad that a truck can reach directly costs less than one that needs a pump or barrows. Most slabs also need a compacted gravel base, priced separately, which the gravel calculator sizes.
Concrete pad estimate for small jobs
Suppliers often charge a short-load fee below a minimum order, so a very small pad can cost more per cubic metre. For pads under about one cubic metre, premixed bags may be cheaper.
Slab cost calculator reference (example rates)
| Slab | Thickness | Total cost | Per m² |
|---|---|---|---|
| 3 × 3 m | 100 mm | 411.75 | 45.75 |
| 6 × 4 m | 100 mm | 1,098.00 | 45.75 |
| 6 × 4 m | 150 mm | 1,287.00 | 53.62 |
| 10 × 6 m | 100 mm | 2,745.00 | 45.75 |
Illustrative only; use your local rates.
Concrete Slab Cost Calculator FAQ
How do I estimate concrete slab cost?
Add the concrete cost (volume × price) to labor and reinforcement cost per square metre times the area.
What does the estimate leave out?
Site prep, excavation, base gravel, permits, and decorative finishes.
Does a thicker slab cost much more?
It raises the concrete cost but not labor or reinforcement, so the total rises less than in proportion.
Does this work for a suspended or roof slab?
No. It is for slabs on grade; structural slabs need engineering and formwork costs.