Concrete Mix Calculator
Written by Thierno Sadou Diallo, formula verified per our methodology • Last checked on 9/5/2026
For a 350 kg/m³ concrete mix (the standard ratio for reinforced concrete), 1 m³ of concrete requires 350 kg of cement, 500 L of sand, 700 L of gravel, and 175 L of water.
Explanation
A mix of 350 kg of cement per cubic meter is the most commonly used standard for structural reinforced concrete (slabs, strip footings, columns, driveway slabs), offering a good balance between strength and cost. This mix roughly corresponds to the "1-2-3" volume ratio used by many professionals as a simple benchmark: 1 volume of cement, 2 volumes of sand, 3 volumes of gravel, topped up with about half a volume of water. This calculator starts from an already-known concrete volume (in m³) to directly give the amounts of each material to order or weigh out. For a less mechanically demanding project (a non-trafficked slab, a light foundation), a lower mix (250 to 300 kg/m³) may be enough; for a heavily loaded project or one exposed to frost, a higher mix (400 kg/m³ or more) is sometimes recommended — this calculator specifically applies the standard 350 kg/m³ mix, to be scaled proportionally if a different mix is required for your project.
Example: 1 m³ of concrete
Inputs
Concrete volume: 1 m³.
Calculation
Cement = 1 × 350 = 350 kg. Sand = 1 × 500 = 500 L. Gravel = 1 × 700 = 700 L. Water = 1 × 175 = 175 L.
Result
This cubic meter of concrete requires 350 kg of cement, 500 L of sand, 700 L of gravel, and 175 L of water.
Frequently asked questions
How do I find the volume of concrete needed for my slab or footing?
Volume is calculated by multiplying the area by the thickness (for example, a 10 m² slab at 15 cm thick is 10 × 0.15 = 1.5 m³). Our concrete volume calculator lets you do this directly from the project's dimensions.
Does a 350 kg/m³ mix suit every use?
It's the standard mix for typical structural reinforced concrete, but some projects call for a different mix: a lower mix (250-300 kg/m³) is often enough for a light, non-trafficked slab, while a higher mix may be recommended for heavily loaded structures or ones exposed to harsh weather (repeated freeze-thaw cycles). If in doubt about a load-bearing structure, a professional's advice is recommended.
Do these amounts apply to ready-mix concrete delivered by truck?
No, these amounts are for concrete you mix yourself from separate cement, sand, and gravel (with a concrete mixer, for example). For ready-mix concrete delivered by truck, the batching plant prepares the requested mix directly: you just need to specify the volume and desired strength class, without calculating the material proportions yourself.