Concrete Mix Ratios Explained: From C10 to C40 in Layman’s Terms

Concrete Mix Ratios Explained: From C10 to C40 in Layman’s Terms

Concrete is the backbone of modern construction, from garden paths to towering skyscrapers. But if you’ve ever read a project specification or spoken with a contractor, you’ve probably heard terms like C10, C20, or C40 concrete mix thrown around. To the untrained ear, it sounds technical and confusing. What do these numbers mean? How do they affect your project? And which one should you use?


In this guide, we’ll break down concrete mix ratios—specifically the grades C10 through C40—in simple, everyday language. By the end, you’ll have a clear understanding of what each mix does, why it matters, and how to choose the right one with confidence.


What Does “Concrete Mix” Mean?

A concrete mix is essentially a recipe. Just like baking a cake requires the right ratio of flour, sugar, and eggs, making concrete requires the correct proportions of cement, sand, gravel (or stone), and water.


The “C” in concrete grades like C10 or C40 stands for “concrete,” and the number represents its compressive strength, measured in newtons per square millimetre (N/mm²), after 28 days of curing.


The higher the number, the stronger and more durable the mix.


Breaking Down Concrete Mix Ratios: C10 to C40

Let’s walk through the different grades one by one. We’ll explain what each mix is made of, where it’s used, and why.


C10 Concrete Mix

Layman’s Terms: C10 concrete mix is like the “light-duty” mix. It’s not designed to hold heavy loads but works perfectly for general groundwork and simple projects around the home.


C15 Concrete Mix

Layman’s Terms: Think of C15 as a step up from C10. It’s strong enough for driveways or floors that won’t face heavy vehicles or machinery.


C20 Concrete Mix

Layman’s Terms: This is a versatile mix. C20 is often used in domestic construction where strength is important but extreme load-bearing isn’t required.


C25 Concrete Mix

  1. Strength: 25 N/mm²
  2. Typical Mix Ratio: 1:1.5:3
  3. Common Uses:
  4. Residential foundations
  5. Reinforced bases for garages and workshops
  6. Medium-load driveways and pavements

Layman’s Terms: C25 is the “standard” for many home foundations. It’s strong enough to support small buildings and reinforced work.


C30 Concrete Mix

Layman’s Terms: If you expect cars, vans, or regular heavy traffic, C30 is a reliable choice. It’s durable and resists cracking under pressure.


C35 Concrete Mix

Layman’s Terms: C35 is where we start talking about serious strength. This grade is often used in commercial projects where safety and durability are critical.


C40 Concrete Mix

Layman’s Terms: C40 is the heavyweight champion of concrete mixes. It’s built to last and withstand extreme pressure, making it ideal for major infrastructure projects.


How to Choose the Right Concrete Mix

When selecting a concrete mix, consider these three factors:

Load-bearing requirement:


Location and exposure:


Cost vs. performance:



Why Work With Professionals Like Pro-Mix Concrete

Mixing concrete isn’t just about proportions—it requires precision, timing, and the right materials. Choosing Pro-Mix Concrete ensures:

Instead of worrying about getting the ratios right yourself, you get peace of mind knowing your mix is prepared and delivered to exact specifications.


FAQs About Concrete Mix Ratios

Q1: What is the best concrete mix for a driveway?

For light cars, C20 or C25 is suitable. For heavier vehicles or frequent traffic, go for C30.

Q2: Can I use C10 for foundations?

Not recommended. C10 is too weak for structural loads. For house foundations, C25 or higher is safer.

Q3: How much water should I add to concrete mix?

The water-cement ratio varies, but a typical range is 0.4–0.6. Too much water weakens the concrete; too little makes it hard to work with. Professional suppliers like Pro-Mix Concrete get this balance right for you.

Q4: Is stronger always better?

Not necessarily. Using C40 for a garden path is overkill—and more expensive. Always match the grade to the project’s needs.

Q5: How long does concrete take to cure?

Concrete gains most of its strength in the first 28 days, but it begins setting within hours. Avoid heavy loads on new concrete for at least 7 days.


Final Thoughts

Understanding concrete mix ratios doesn’t have to be overwhelming. Think of each grade—C10 through C40—as a tool, each suited to a different job. The trick is matching the right strength to the right project.


By working with trusted suppliers like Pro-Mix Concrete, you can rest assured that your concrete is mixed to exact standards, saving you time, money, and stress while ensuring your project stands the test of time.