Concrete Ballast Calculator

Calculate how much ballast you will need

How our calculator works

• Input the width and length in metres for your floor area, followed by the depth you need in millimetres. The cubic metres for the area will then automatically be calculated using Length x Width x Depth
• Once the cubic metres for the area is calculated behind the scenes, it will then be converted into the weight of the ballast you will need in total. For 1 cubic metre of floor area you will need 1,750 kilograms of ballast
• Once you've got your total ballast needed, you can then input the size of the bags you'll be using. Bag size come as small as 20-25kg and can be as large as 850kg-1,000kg.
• Lastly, the calculator will let you know the amount of bags you need by dividing the total ballast amount by the size of the bags you're buying. It's as simple as that.

Getting the Right Concrete Ballast Mix Ratio

When mixing concrete for any project, getting the right ballast-to-cement ratio is key. Whether you're laying a simple garden path or pouring a solid foundation, the mix needs to suit the job. It’s not just about how much ballast you need, but making sure the strength and durability match the load the surface will bear.

There are a few standard ballast mix ratios, depending on what you're working on:

• 1 to 5 mix: One part cement to five parts ballast is a common general-purpose mix. It’s ideal for paths, paving slabs, and concrete panels. This mix has good watertight properties, which makes it useful for walls and panel-based structures.
• 1 to 6 mix: If you need something stronger, such as for a driveway, garage floor, or heavy-use patio, go for one part cement to six parts ballast. This mix holds up well under weight and pressure, making it suitable for areas where durability is essential.
• 1 to 8 mix: For foundations and load-bearing surfaces, use one part cement to eight parts ballast. This is the mix you'd want for shed bases, deep footings, or any structure that needs solid ground support.

Picking the wrong mix can lead to weak concrete, wasted materials, and structural issues. In some cases, adding reinforcing bars can boost strength, but the cement-to-ballast ratio is still crucial.

Since cement is the binding agent that holds everything together, make sure you're using high-quality ballast and cement. Loose ballast, incorrect ratios, or poor materials can lead to weak, cracked, or even unsafe concrete surfaces. Always measure properly and mix thoroughly to get the best results for your project.