Concrete Calculator

Use our free concrete calculator to estimate concrete volume, 25 MPa mix, foundation, slab, and ready mix requirements for projects in South Africa.

Note: This calculator provides an estimate only. Actual requirements may vary based on project specifics, site conditions, and construction techniques. Prices are estimates based on South African market rates and may vary based on supplier, location, and market conditions. A 25 MPa mix is suitable for most residential applications including slabs, footings, and columns.


A concrete calculator helps homeowners, contractors, and DIY users quickly estimate how much concrete is needed for a project without guessing or wasting material. Instead of manually working out cubic meters using formulas, the tool automatically calculates the correct quantity for slabs, floors, foundations, pads, walkways, and more.

Whether you are mixing onsite, buying bags, or ordering ready mix concrete, accurate measurement prevents over-ordering and extra costs. It also ensures you do not run short during a pour, which can weaken a slab or create poor structural results.

Builders in South Africa often compare prices from suppliers like Cashbuild, PPC, Afrisam, Buco, and others. A calculator makes the ordering process faster, allowing you to know how much you need before calling a supplier or visiting a store.


Different projects require different mixes. Here are common examples builders use:

  • Foundations – stronger mixes with higher cement content
  • Floor slabs – medium strength
  • General small projects – standard premix options

If you are unsure which mix to use, our calculator gives estimates that work for most applications. For detailed requirements, always check SANS specifications or consult a structural engineer.


South Africans often search for calculators that match their project needs. Here are the most popular ones and how they help:

Foundation Concrete Calculator

Ideal for footing, pad, and strip foundations. It removes guesswork and gives accurate volume estimates for structural work.
Use Foundation Calculator

Sand and Cement Calculator

Perfect for plastering, brickwork, rendering, and general mixing. It calculates exact quantities so you know how many bags of cement and how much sand you need.
Use Sand & Cement Calculator

Slab and Floor Calculator

Used for garage floors, house slabs, and yard surfaces. It converts your project measurements into cubic meters and estimated bag counts.

Ready Mix Concrete Calculator

Great for users who prefer to order from a supplier instead of mixing on site. Many builders use this when planning deliveries from major brands.

Concrete Bag Calculator

Helps DIY homeowners plan smaller projects and determine how many 20kg or 50kg bags should be purchased.

Use the calculator above to enter:

  • Length
  • Width
  • Thickness

Then select your project type. Once the calculation is done, you can proceed directly to:

  • Ordering your sand and cement
  • Calculating bags required
  • Planning your ready mix delivery
  • Using our linked tools for foundations or plaster calculations

This ensures an accurate, cost-effective building process from start to finish.

Frequently Asked Questions about the Concrete Calculator South Africa

What is a Concrete Calculator?

A Concrete Calculator South Africa is a tool that helps you estimate how much concrete you need for a slab, foundation, driveway, or any building project. Instead of doing manual calculations, the tool works out the volume based on your measurements.

How do I calculate how much concrete I need?

Simply measure the length, width, and depth of your project area and enter the values into the calculator. It converts the measurements into cubic meters, giving you a precise estimate for your concrete requirement.

How many bags of concrete will I need?

The calculator can estimate how many 20kg or 50kg cement bags you will need based on standard South African mix ratios. This helps ensure you purchase the right amount without running short.

Can the calculator be used for slabs and foundations?

Yes. Whether you are building a house slab, floor, strip foundation, fence post, or walkway, the calculator provides accurate volume calculations suitable for small and large construction projects.

Does it calculate sand and stone as well?

Yes. Along with the total concrete volume, the tool can estimate how much sand, stone, and cement is needed for your mix, making planning and budgeting much easier.

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