Calculating the concrete requirement or the required quantity of concrete in m³ is not at all difficult.
Then finding out how many packs or bags of dry concrete/dry concrete mix you have to buy for the calculated volume is a bit trickier. So if you want to mix concrete to fill a certain cubic meter and want to know how many bags of 25 kg concrete, 35 kg concrete or 40 kg concrete each can be bought, then you’ve come to the right place.
We show you how to calculate concrete quantities and how much dry mix you need. Nevertheless, when buying, pay attention to the information on the packaging and, if in doubt, ask a local specialist seller.
Cubic meters and the required amount of concrete: How many kg of ready-mixed concrete / dry mix are required for 1 m³ volume? Here you get answers and tips for calculation and determination.
Calculating Concrete Requirements: How many cubic meters do i need?
The first step in determining the concrete mixing requirements is, of course, the calculation of the volume to be filled.
Classically, a cuboid with height, width and length is calculated here. If you want to make concrete furniture yourself, you may also have other shapes in mind, such as cylinders, cones or the like. There are also the right formulas for this. For example, for calculating a circle section to determine the base areas of individual parts.
But let’s stick to the cuboid as the simplest body to be calculated. For the rectangular area you want to fill with concrete, first measure the height, width and length in meters. For example, let’s assume a room with a width of 2m and a length of 3.6m. The concrete is to be poured 10cm, i.e. 0.1m high. This results in the following calculation:
2m x 3,6m x 0,1m = 0,72m³
This means that you need 0.72 cubic metres of concrete for the floor of the room. If you need help calculating or want to check your results, you can use the calculator on your PC, Mac, smartphone or tablet. Or you can visit an online calculator for cubic meters, like this one (click here).
Calculate Cylinder Volume
As can be seen above in the picture, concrete cylinders are well suited as decoration and demarcation in the garden. With a cylinder as a geometric shape, the volume calculation is a bit more complicated, but not impossible either. What you need is on the one hand the height of the concrete cylinder and on the other hand its base area. The height can easily be determined with a ruler or folding ruler. Calculate the base area as follows:
A=π*r² (A = area; r = radius) / or alternatively: A=(π*d²)/4 (d = diameter)
Use a value for r or d in meters for the calculation. Also use a meter for the height of the cylinder.
Then simply calculate V=A*h (V = volume; h = height) for the volume. A more detailed explanation and calculation examples for cuboids, cylinders and spheres can be found here (click).
How many kg on Ready-Mixed Concrete do i need for 1m³?
This is how 1m3 cube looks like.
For the first calculation example, let’s assume 40 kg of ready-mixed concrete that you want to use for mixing concrete.
Once you have finished your mould for pouring the concrete, measured everything accurately and calculated the volume, you assume a rough figure of 21 litres of concrete after mixing 40 kg of concrete mixture.
Since 1m³ corresponds to a volume of 1,000l, you therefore calculate 1,000 / 21. 48 rounded bags of ready-mixed concrete of 40 kg each or a total of 1,920kg of ready-mixed concrete per cubic meter are required.
However, you must also make sure that there are different types of concrete, such as fast concrete and similar types.
Various instructions and regulations therefore also state that you need about 56 packs of dry concrete of 40kg each for 1m³, which results in about 17.86 litres of liquid concrete per pack.
An important tip: look at the packaging when buying the dry concrete or talk to the seller in the trade / DIY store – he should be familiar with the quantity of concrete to be expected and the quantity of water to be added beforehand.
How long does Concrete have to harden?
Despite its relatively simple components, concrete is a complex mixture of materials that only reaches a so-called standard strength or minimum compressive strength after about one month.
Once you have successfully calculated the volume of the room to be filled and know how many kilograms of ready-mixed concrete you need for the cubic meter quantity determined, then the concrete is easy to mix and pour. Then wait at at least 12°C and average humidity for about 28 days.
Then you can process the cast parts further or build on, seal, paint or otherwise process the cast concrete surface. Further facts and tips on the composition of concrete and the period during which concrete has to harden can be found in this article (click)..
Concrete Surfaces as Floor, wall and roof
First of all: there is a difference between concrete and screed. We have already dedicated an article to this topic with all the facts and distinguishing features worth mentioning.
The difference between concrete and screed is not necessarily the most important thing when treating concrete as the floor or floor of a hall, workshop, etc.
If you know what you are dealing with, you can easily take measures for smoothing, sealing and upgrading the concrete surface. For service providers who offer work on concrete (floor, facade and roof), we have the right products and articles ready.
Systems for concrete sealing
Concrete sealing has several advantages after tempering, pouring and curing. Smooth (but non-slip), sealed and compacted concrete surfaces are water-repellent, breathable and self-cleaning.
They require little maintenance and are strong against environmental influences, microorganisms such as bacteria, algae, fungi and lichens.
Cleaning can be reduced to a minimum and unlike porous left concrete surfaces, sealed concrete floors, concrete facades and concrete tile roofs are also less susceptible to damage and chipping due to erosion, frost and other influences.
Details about our products and systems can be found on our homepage.
Determining Concrete volume SUMMARY
If you want to mix and pour concrete, you must first of course calculate the requirement for ready-mixed concrete, fast concrete or similar concrete mixed with water.
You can find out exactly how much dry concrete mix you ultimately need by looking at the information on the packaging or by talking to the specialist salesperson.
There are also service providers who not only help you calculate the required quantity, but also supply finished concrete for casting.
Other service providers are responsible for the processing, smoothing, silicification and/or sealing of concrete elements – ask those for our BECOSAN® and deepEX® brand products.