Calculation of the volume of lumber. How many boards in a cube: how to make calculations using various methods How to calculate a cubic meter of wood

Before buying a floorboard, you need to calculate how many cubes of lumber you need for a device of a certain design. In this case, an accurate calculation can be done using a conventional calculator, knowing the area of ​​\u200b\u200bthe room and the thickness of the board. Such skills will be useful to you not only in order to calculate the volume of lumber for flooring, but also if you decide to build a house, because wood products are used to build various structures.

Since the price of all lumber during the sale is charged per cube, it is important to be able to calculate the need for this particular unit of measure. This is how not only the number of boards is counted, but also other lumber, for example, timber, slats, etc. The thing is that products with the same cross section can differ in length. Therefore, after determining the volume, you can understand how many floorboards will be in one cube.

It is important to know: when buying boards made of precious wood, the products are sold by the piece. The thing is that the price of such coatings is too high, and when calculating in cubes there is a small error.

When calculating, it is better to use a regular calculator. So you can get a more accurate result and take into account all the nuances of the future design of the house. Although if you need to find out how many cubes of a board, for example, 50 mm thick, will be needed for flooring, then you can use the online calculator. Such a simple calculation he can perform correctly. However, it's always a good idea to be able to count the amount of lumber by hand.

When building a house or laying a floor, the calculation is carried out in the same order:

1. First you need to calculate the total volume of lumber in cubes. Knowing the moisture content of wood, you can determine the weight of the entire material. This will help you decide which shipping method you choose.

Tip: when ordering a carrier, it is better to indicate an overweight (10-15% more). So you will not have problems with the load, because the moisture content of the wood declared by the manufacturer may be a little more or less.

1. Further, knowing the dimensions of the boards, you need to calculate the volume of one element. Then you can find out how many products will be in the cube. Multiplying this number by the number of cubes will give you the total number of floorboards for your floor design.

However, such a simple calculation is applicable for edged elements, because they are processed from all sides and there are practically no gaps when they are stacked. To calculate how many cubes of unedged boards are needed for flooring, you will have to use a correction factor, because due to the raw sides of the product, there will be too many gaps when stacked.

Calculation example

Suppose that in a house you want to lay a room with a floorboard 50 mm thick with dimensions of 5x6 m. We calculate the volume of lumber and the number of products in the following sequence:

• We find the area of ​​​​the room: 6x5 \u003d 30 m².
• Since we decided to use a board with a thickness of 50 mm or 0.05 m, the lag step can be made 1 meter.
• Knowing the thickness of the element and the area of ​​\u200b\u200bthe room, we get the volume of lumber: 30 m² x 0.05 m = 1.5 m³.
• Now using the calculator, you can calculate how many floorboards you need. To do this, knowing the dimensions of the floorboard, we calculate its volume: 2 m x 0.05 m x 0.13 m = 0.013 m³. Now we divide the total volume of lumber by the resulting number for an element with a thickness of 50 mm: 1.5: 0.013 \u003d 115 boards.

Thus, using a conventional calculator, you can calculate the need for other lumber for building a house: lining, timber, slats.

Almost everything in our world has its own measurement value. We measure oil in barrels, coal in tons, the population of countries in thousands, millions.

We take as a basis a value that can specifically designate the object that we measure. When the question arises of how to calculate the cubature of a board, we are no longer talking about the mass of an object, since wood has a completely different density, and one tree has differences from another. In addition, boards of the same breed will have different weights depending on their moisture content.

For the convenience of calculating the cubature of the board, volume measurement formulas are used.

It is enough to recall school mathematics and the necessary formula by which to multiply the width, length and height. For the calculation to be correct, it is necessary to adjust all parameters to one value, for example, in centimeters or decimeters. It is most convenient to take meters as a basis. Thus, having multiplied three times in meters, we get m³ or cubic capacity.

Note. To calculate the cubature of the board, special formulas are used.

cubature boards

Boards may have differences in width, length, thickness. In addition, they are sold unedged and edged. Often, lumber has its own generally accepted standards, which make it easier to calculate cubic capacity.

For ordinary material sizes, there are already calculated volumes, which are systematized in tables for measuring the cubature of boards. Therefore, to determine the volume of the material, you simply need to open the table with the indicated dimensions and calculate the volume.

But, in order to do this, you must have these tables with you. Otherwise, in the absence of such, the cubature of the edged board is calculated, having previously determined the thickness and length. These are the main dimensions that meet the requirements for lumber. Each individual material is different. For example, a board with a thickness of 25 mm is used to create a crate, and 50 mm for subfloors. Next, you need to measure the width of the board.

In the case of a cut board, everything is simple, since the material is cut to give one width. Further, using a calculator, all values ​​\u200b\u200bare multiplied among themselves. With a board length of 5 m, a thickness of 50 mm and a width of 25 cm, the volume of the material will be:

5 x 0.050 x 0.25 = 0.0625 m³

After multiplying the resulting number by the number of boards, we get the total volume of material.

The formula for calculating the cubature of boards

V = L x h x b

L - length

h - height

b - width

Determination of the number of boards in a cubic meter

1 m 3: V = N

In order to determine the cost of a particular type of board, with known volume values: V x price 1 m 3.

There is one more point that you need to pay attention to when determining the cubature of boards - the nominal length is exactly 6.1 - 6.2 m, but this is not taken into account when selling. Often this is important in the case of buying a large amount of material. For example, let's take a board with dimensions of 150 x 20 mm.

Having made simple calculations, we get the number of boards in 1 m 3 - 55, 5 pieces. So, in the cubature of the board 6 m there are exactly 55 pieces, in total, when calculating, we get the value of 0.99 m 3. In essence, the overpayment for the cubature of the board will be 1% of the exact price. For example, at a cost of 4,995 rubles, we pay 5,500 rubles.

Unedged board

Calculation features

The calculation of the cubic capacity of an unedged board is somewhat complicated, since the material does not have the same width between different boards, but also in each board individually. This is explained quite simply - the tree does not have the same diameter.

It is clear that it is wider at the bottom, narrower at the top. Thus, the width of the edged board does not fall under any standards. How to be in this case? Use different formulas to calculate. The width of the board is measured for convenience in the middle of the length. This is how you get the average width. This counting method works well if the batch of material is small.

For industrial volumes

This method is not suitable, because the work will be very slow, and this is not profitable. For such cases, experts have developed the so-called unedged board cubature. The volume in it is obtained by measuring and experimenting, in other words, using many measurements and calculating the average value of the width.

Of course, this cannot be called a super accurate way, but the deviations are so small that they should not be paid attention to.

Some wood processing companies use the stack measurement method in practice. To do this, it is not necessary to pre-sort the wood according to width. Specialists take measurements of the length of the board, the average width and height of the stack. The obtained values ​​​​are multiplied among themselves, and the result is multiplied by a coefficient for calculating the cubature of the board, which has an average value of 0.67.

Weighing method

In order to measure the cubic capacity of an unedged board, having obtained the most accurate result possible, the weighing method is used.

Before doing this, it is necessary to measure the moisture content of the material and dense wood. Considering that the edged board is the cheapest material used on objects with the least degree of responsibility, complex calculations are not very justified.

Also, it should be noted that the result that you get will not be much different from the one that can be obtained using the cube.

During the construction of residential buildings

Here, professionals in their field are required to perform many tasks, including: calculation and budgeting before finishing the premises. In addition, you need to calculate the required amount of building materials. It should be noted that this task is quite difficult. Given this, determining the cubature of the board is an important point.

Note. A cubic meter of lumber is calculated using a single method. The type of board does not affect the result.

To non-grooved types wood include: edged board, unedged board.

tongue-and-groove types- these are those that have special grooves for the perfect joining of the boards: flooring, lining,. Please note that when purchasing a grooved board, the calculation is carried out using the working width of the material, without spikes.

Regarding the calculation of the cubature of an unedged board, with a width of one end of 25 cm, and 20 cm of the other, the average value will be 22 cm. To calculate a large amount of material, it is laid out in such a way that the wide part does not differ from the narrow one by more than 10 centimeters.

The main length of the board in the unfolded bundle should be approximately the same. Then, using a tape measure, measure the height of the stack of boards and the width in the middle. The result, which is obtained during measurements, is multiplied by a coefficient with a value of 0.07 - 0.09, which depends on the air gap between the boards.

When roundwood is harvested, first of all they try to accurately calculate its cubic capacity.

The measurement is made in the upper cut, where the diameter will be slightly smaller. When measuring trunks that have a cross section other than round, they try to measure along the narrowest section, passing through the center of annual wood rings.

This technique is used because it allows you to most accurately estimate how much edged lumber will be obtained from one log, which is of the greatest value in woodworking. Obviously, they will be cut based on the diameter of the upper cut.

For the same reason, the ridged part of the trunk, where the difference between the larger and smaller diameters of the cut is large, is preferred to be discarded and not used in the workpiece. All the same, wood will be taken at the sawmill along the upper cut.

When determining the length, measurements are taken with an accuracy of 10 cm, while the length is rounded down. Such accuracy is due to the fact that when felling logs, two cuts are usually made - one higher, the other lower. First do the bottom, then the top - on the other side. falls in the direction where the top of his head leans. The cuts are made so that the bottom one is on the side where the trunk should fall.

In this case, the upper cut is made on the other side, standing in the direction opposite to the most likely fall. During subsequent sawing, the whip is usually sawn with a saw for one cut, but often a cut error is allowed - it can go a little obliquely, because of this, such a large error.

Calculation by cube

In accordance with it, it is possible to determine the volume of each log by taking measurements and selecting a value from the table. In the table, the diameter of the trunk comes in increments of 1-2 cm, and the length is 10 cm. Of course, using the entire cubature table is not very convenient.

This table provides data for the most common top cut diameters and lengths. Usually it is required to calculate the volume for logs up to 6 meters long. It is logs of this length that fit into most standard standard bodies of ordinary ones that are not specialized as timber trucks or timber trailers for tractors, it is in the size of up to 6 meters that the whips are crossed.

Naturally, when the forest is handed over to the sawmill, there is no question of any “approximate” calculations, and it is necessary to apply the full GOST in the final calculation - after all, these are sawmills and the money of foresters who love accurate counting.

Calculation by formula

V=πd²l/4, where d is the diameter of the trunk in the upper cut, l is the length of the log, π = 3.14 - for our calculations, the greater accuracy of this constant is not needed.

This is convenient when there is no GOST at hand, but only. With large volumes of work, even from three or four machines, it will take a lot of time to calculate in this way, in addition, this technique is not standardized and is not an argument in financial disputes.

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Any construction work begins with a project and an estimate, which implies the calculation of the amount of materials. Edged board is one of the most popular materials from the assortment of timber merchants. The basic unit of measurement for any lumber is 1 m 3. However, it is important for the end user to know the number of boards in a cube of a certain length and thickness.

Instruction

Sometimes the manufacturer leaves a label on the materials indicating the price of the package and the exact volume. But often the storekeeper makes the measurement.

The calculation of cubic capacity will depend on the degree of processing of the material, type and grade. For example, edged and unedged boards are calculated differently. Also, for breeds, calculation methods can be different. For coniferous and deciduous, you can use both the measurement and multiplication of the sides, and the standard designed to calculate the volume. The second method is the use of a collection of tables, where each meter of length and one piece of material corresponds to a volume. They are called cubers.

To find the number of cut boards in 1 cube, you need to find out the volume of one of them by finding the product of three quantities, and then divide 1 m 3 by it.

Example:

• Section 150x25 mm
• Length 6 m

The first step is to translate all values ​​​​in meters: 150x25 mm \u003d 0.15x0.025 m

0.15 x 0.025 x 6 \u003d 0.0225 m 3

We determine how many boards are in one cube: we divide 1 m 3 by the cubic capacity (the volume of one board):

1 m 3 / 0.0225 = 44.4 pieces

Calculation may be required, for example, when determining the cost. So, if we take the price per cube equal to 6,500 rubles, then with a cubic capacity of 0.0225 m2, one will cost 146.25 rubles. But often the volume is rounded up to 0.023. And then the materials cost the buyer 149.5 rubles apiece. And when rounding the amount, the overpayment for 1 m 3 is 1%.

The calculation for unedged boards is made differently. If only one piece is purchased, then its length and thickness are measured in the same way as for edged material. But the width is taken as an average. For example, if it can vary from 15 to 23 cm at different ends, then you need to take the value in the middle.

If you want to find the volume of a large number of boards, then they need to be sorted in piles according to the maximum match in length and width. It is better if the error does not exceed 10 cm. The height of the stack is measured with a tape measure in the middle of the board and the length. The result is multiplied by a special coefficient, which depends on the air gap and is 0.07-0.09 units and is taken from the cubature reference book.

The table shows the estimated number of edged boards of spruce, pine, cedar and larch in a cube of lumber. The standard length is taken as 6 m, and the width is from 100 to 250 in 50 mm increments. The thickness is 25-50 mm.

Achieving waste-free lumber production is almost impossible. There are many reasons for this. When sawing logs into lumber of standard sizes, an unedged board is obtained as a by-product. This material is considered consumable, so there are no special requirements for its quality.

Unedged hardwood boards are good as a finishing material. There are many ways to highlight the extraordinarily beautiful structure of a tree. This lumber is also distinguished by the beauty of the unremoved edge.

Unedged lumber: properties and features

The cubature is calculated based on the width, height and length of the board.

As a by-product, this building material has a relatively low price. Therefore, it is widely used for private housing construction as an auxiliary material for rough finishing of premises, etc.
These works provide for the calculation of the number of copies. When selling, this parameter is measured in cubic meters, therefore, it is necessary to calculate in advance the volume required for the room.

The most used specimens are 25 to 50 mm thick, 3 to 6 m long. Having determined the area of ​​the surface to be covered and multiplying it by the thickness of the coating, we obtain the required cubic capacity of unedged lumber. It must be remembered: the thicker the lumber, the heavier it is, the greater the load on the supporting structures of the building.

Measuring the cubature of a board of an unedged board.

However, it will not work to independently calculate the volume according to the dimensions of a separate board, which does not have clear dimensions of the edges. In this case, OST 13‑24 (Fig. 1) and GOST 5306-83 will help to calculate correctly.
Three options for calculating the volume are defined: batch, piece, selective.
When purchasing a package, you need to pay attention to the following:

• the front end of the package must be aligned;
• rows should not contain overlapping boards;
• the width of the package must be constant along the entire length;
• the displacement of the extreme boards inward or outward is allowed no more than 100 mm.

The piece method is understandable by definition. The sample calculation method is not used when purchasing a small amount of material, so it is not practical to determine it for small lots.

Determination of cubature using tables

Doc.1 gives examples of how to calculate the cubature in batches. To do this, you need to measure the length, width, height of the package, calculate its volume. Then multiply the result by the stacking factor. This factor is given in Doc.1. To calculate the size of a bag with a material 25 mm thick, the resulting volume must be multiplied by 0.61 or 0.66 (depending on the moisture content of the wood).
How to calculate the cubic capacity by the piece, you can look at fig. 2. The sequence of piece calculation:

• choose thickness (mm), length (m) and desired width (mm);
• according to the known covered area, the required amount of material (pieces) is calculated;
• according to the diagram in fig. 2 determine the volume of one copy;
• find the required value from a known quantity.

The scheme in fig. 2 defines the parameter of one board. Its length is limited by the range from 3 to 6 m. The gradation in length is the same for everyone, but the gradation in width is different.
Table 1 lists the thickness values ​​and the corresponding width gradation. This will give you the opportunity to decide what to expect when buying.
Table 1

The tabular method of any calculations is the simplest. However, the analysis of the data presented in Fig. 2 shows that the change in cubature with a change in length obeys a linear law:
V = kL+b, (1)
where V is the volume (m 3), L is the length (m).
Table 2 contains the values ​​of the coefficient k and the constant term b for boards with a thickness of 50 mm.
table 2