How to Calculate the Amount of Concrete You Need for Any Job

If you don’t work with concrete or measure areas frequently, you might be wondering: How much concrete do I need for my job? Understanding how to calculate the amount of concrete you need is simple once you know the basic math involved.

Here’s a straightforward method to help you figure it out.

Concrete Calculation Formula: The Basics

To calculate the amount of concrete required for your project, you can use a simple mathematical formula:

Length × Width × Height = Concrete Volume (in cubic meters)

This formula is the standard method for calculating concrete volume and is widely used in construction projects around the world.

Example: How to Calculate The Amount Of Concrete You Need for a Garage

Let’s say you’re pouring concrete for a garage floor that measures 6 meters by 9 meters and needs to be 100mm (0.1m) thick. You also need to account for footings that are 200mm x 200mm.

Floor Area:
6m × 9m = 54m²
54m² × 0.1m (thickness) = 5.4m³ of concrete
Footings:
For footings, measure the perimeter: 9m + 9m + 6m + 6m = 30m
Footing Volume:
30m × 0.2m × 0.1m = 0.6m³ of concrete (Note the footing area is only measures at .1m thick as the floor area measurement already allows for the top .1m of concrete)

Total Concrete Required:
5.4m³ (floor) + 0.6m³ (footings) = 6m³ of concrete

This method works for any similar concrete project, whether it’s a foundation, patio, or other types of slab.

Use Our Concrete Measurement Calculator <<<

How to Calculate The Amount Of Concrete You Need for a Driveway

If you need concrete for a driveway, the calculation method is the same. Typically, driveways are poured 100mm thick, with thicker edges measuring 200mm x 200mm. Here’s how you’d calculate the concrete volume for a driveway that is 3.6 meters wide and 27.6 meters long:

Driveway Area:
3.6m × 27.6m = 99.36m²
99.36m² × 0.1m (thickness) = 9.94m³ of concrete
Footings:
The perimeter of the footings:
3.6m + 3.6m + 27.6m + 27.6m = 62.4m
Footing Volume:
62.4m × 0.2m × 0.1m = 1.24m³ of concrete

Total Concrete for Driveway:
9.94m³ (surface) + 1.24m³ (footings) = 11.18m³ of concrete

Understanding Concrete Costs

The cost of concrete varies by location, but in New Zealand, expect to pay between $250 to $400 per cubic meter. For a typical 5m³ truckload, you could pour a 50-meter-long path that is 1 meter wide and 100mm thick.

For the driveway example above (11.18m³), assuming a cost of $238 per cubic meter, the total cost would be:

$238 × 11.18m³ = $2,658.46 (plus GST)

Tips for Ordering Concrete: Call Your Local Supplier

When in doubt, reach out to your local ready-mix concrete supplier for assistance. They can help you determine the exact amount of concrete you need and provide valuable advice about:

Concrete strength (measured in MPa)
Reinforcement and decorative options (e.g., stamped or colored concrete)
Delivery logistics and scheduling
Concrete pumps for difficult-to-reach areas

Providing your supplier with the length, width, and thickness of your project will ensure an accurate calculation and avoid costly mistakes.

Converting Cubic Meters to Cubic Yards

If you’re working in cubic yards (as is common in some countries), here’s how to convert the amount of concrete needed:

1 cubic meter = 1.3 cubic yards
Add 30% to your cubic meter total to account for variations in measurements.

For example, if you need 1.8m³ of concrete, converting it to cubic yards involves:

30% of 1.8m³ = 0.54m³
1.8m³ + 0.54m³ = 2.34 cubic yards of concr

Best Practices for Ordering Concrete

While calculating concrete volume can be precise, it’s always a good idea to round up. If your project is small (less than 1m³), consider ordering 1m³ to account for minor variations. For larger jobs (under 5m³), add an extra 0.2m³ to your order to avoid running out mid-project.

How To Calculate The Amount Of Concrete You Need: Summary

Now that you know how to calculate the concrete required for your project, you’re ready to place your order. Whether you’re working on a driveway, patio, or foundation, use the formulas above to estimate the volume and ensure you have enough concrete for your job.

Need help calculating the concrete for your project? Don’t hesitate to reach out to your local concrete supplier for expert advic