Concrete Mix Ratios for Flooring

All mixes for all concrete projects

Regardless on if you are a DIY expert looking to learn more about concrete mix ratios to line your garage, driveway or patio, or a seasoned concrete contractor looking for the best mix ratios, British Concrete Polishing has the answers for both needs.

Understanding concrete mix ratios is a must to make sure you are creating the right mix for your environment and project. This will help you get the most use out of your flooring and ensure a lasting and safe structure.

What is the best concrete mix?

We'll be going into more detail on the various mixes further below, but if you're here for a quick answer, a solid concrete mix ratio for your floor is typically:

1 part Cement
2 part Sand
4 part coarse aggregates

Bear in mind that while mixing it's vital that the concrete is placed within a half hour window to ensure a consistent pour. A square headed shovel is ideal for producing an even finish.

Understanding concrete grades

Essentially a concrete grate is the minimum strength a concrete floor be be at 28 days after laying. This is also the minimum window to wait before polishing the floor with a diamond grinder. In order to understand the acronyms for the concrete grading formula, it has been conveniently simplified below:

• M – stands for mix
• MPa (Megapascal) – MPa is a unit used to measure the compressive strength of concrete. It indicates how much pressure the concrete can withstand before breaking. The higher the MPa rating, the stronger and more durable the concrete. Contractors rely on MPa values to ensure the concrete meets structural requirements for different applications.
• PSI (Pounds per Square Inch) – PSI is another measurement used to determine concrete strength, specifically its ability to handle compression. Different concrete mixes have varying PSI levels, typically ranging from 2,500 to 5,000 PSI, depending on their composition and intended use. Higher PSI concrete is used for heavy-duty structures, bridges, and industrial flooring, while lower PSI mixes are suitable for residential and light-duty projects.

Concrete Grade	Mix Ratio (Cement : Sand : Aggregates)	(MPa)	(psi)
M5	1 : 5 : 10	5 MPa	725 psi
M7.5	1 : 4 : 8	7.5 MPa	1087 psi
M10	1 : 3 : 6	10 MPa	1450 psi
M15	1 : 2 : 4	15 MPa	2175 psi
M20	1 : 1.5 : 3	20 MPa	2900 psi
M25	1 : 1 : 2	25 MPa	3625 psi
M30	Design Mix	30 MPa	4350 psi
M35	Design Mix	35 MPa	5075 psi
M40	Design Mix	40 MPa	5800 psi
M45	Design Mix	45 MPa	6525 psi
M50	Design Mix	50 MPa	7250 psi
M55	Design Mix	55 MPa	7975 psi
M60	Design Mix	60 MPa	8700 psi
M65	Design Mix	65 MPa	9425 psi
M70	Design Mix	70 MPa	10150 psi

Commercial concrete mixes

This table provides a clear breakdown of C10 to C40 concrete grades, their typical environments, and common applications. Whether you're working on domestic projects like driveways and patios or commercial structures such as roads and multi-storey buildings, this guide helps you choose the right concrete mix for your needs. Each grade varies in strength and durability, ensuring the right balance between structural support and cost-effectiveness. Use this as a quick reference when selecting the best concrete for your project:

Concrete Grade	Environment	Common Uses
C10	Domestic & Commercial	Used for patio slabs, pedestrian pathways, and general domestic outdoor work.
C15	Domestic & Commercial	Used for lining curbs, floor bindings, and small-scale domestic and commercial projects.
C20	Mostly Domestic	Ideal for strong floor foundations, garages, driveways, and workshop floors. Supports machinery and heavy-duty use.
C25	Domestic & Commercial	A highly versatile mix used for building foundations, flooring, and general construction projects.
C30	Commercial	The lowest grade used in road, driveway, and heavy-duty flooring construction. Can withstand constant vehicle traffic and harsh weather.
C35	Commercial (Large Scale)	Durable and hard-wearing concrete used for structural support, external walls, and multi-storey car parks.
C40	Commercial & Industrial	Used for strong support beams, large foundations, and high-traffic roads. Resistant to corrosion, making it ideal for farm and laboratory environments.