How is the area of a room calculated? Why an employer should adhere to the rules. How to correctly calculate the area of walls with a complex surface

What is the easiest way to calculate floor area?

So, a situation has arisen when you want to find out what the square footage is in a particular room. And, of course, it’s not the walls that interest you, but only the floor. There may be many reasons for asking this parameter. For example, the house has just been completed, and you want to find out how accurately the builders fulfilled your wishes. Or in the house book only the useful, living area of a country estate is indicated, and utility buildings are not taken into account, but you urgently need their redevelopment. In general, no matter what reason you give, it will be valid. Therefore, we take out a measuring tape and a calculator.

Floor area calculator

Please indicate the dimensions.

The standard option is a rectangular room, even a schoolchild knows how to calculate the floor area, since this formula is taught in geometry at the very beginning of studying this science. All you need to know is the length and width of the room, these values are multiplied, and the resulting result will correspond to the required quadrature of the room. That is, the formula will look like this: S = a. b, Where a And b- two sides of a rectangle, which in our case is the floor. Built-in wardrobes will not spoil the overall picture at all, especially if the quadrature is necessary for installing suspended ceilings, in which case the sections are simply not taken into account.

It’s another matter if, for example, there is a fireplace. Here the area of the room is calculated based on what it is needed for. If you assemble the same stretch ceiling, then you can forget about the fireplace, especially in the case when the pipe runs deep into the wall and is not attached to it. But if you plan to lay parquet or laminated boards, before calculating the floor area, you need to measure the fireplace and subtract the area it occupies from the square footage of the room. The same is true with a built-in wardrobe, which will only interfere when pouring screed or other work, so it is better to simply disassemble such a structure while finishing is being done.

Calculation of floor area in an irregularly shaped room

Houses and apartments with a standard layout usually consist of rooms with a rectangular or square outline, but in some buildings you can find rooms with niches and alcoves. In this case, the floor geometry becomes significantly more complicated, which creates certain problems when installing frames for suspended ceilings or laying patterned parquet floors. Judge for yourself - for the first time you enter a spacious hall, which at the end has a long and rather narrow appendage, and not even located at a right angle. Here it is no longer enough to simply multiply the lengths of two adjacent walls, especially since there are significantly more of them.

However, there is a way to calculate the floor area, although it requires the ability to mentally divide the space into separate fragments. That is, you need to take the apartment plan and find simpler ones in the complex geometric shape of the hall: squares, triangles. For example, if the shape of a room resembles the letter “G”, it means that two rectangles are connected in it, cut one off from the other and separately calculate the area for each, and sum up the calculation results.

If an appendage, an alcove, for example, is not located at a right angle to the main part of the room, it means that a triangle has been squeezed between two rectangles, the two sides of which converge at 90 degrees. Its area is calculated simply S = (a . b)/2, where a and b are the legs. If there is no right angle, another formula is needed: S = √(р. (р – а) . (р – b) . (р – с)), here a, b and c represent the sides of the figure, and p is the semi-perimeter and is calculated as follows: p = (a + b + c)/2.

It is worse if part of the room has the outline of some part of a circle (or, if viewed in volume, a segment of a cylinder). Of course, it may well happen that the closed loggia, inseparable from the living room, has the shape of a regular semicircle. In this case, we calculate its area using the formula S = πR2/2 and sum it with the quadrature of the hall. The most difficult thing here is to find the center of the circle by inscribing it in a square; the intersection of the diagonals will give the desired point, from which we draw and measure the radius R.

Determining the area of a segment is more difficult; for this there is a formula F = (απ/180o – sin α)R2/2, where α is the angle between the radii R drawn from the ends of the chord limiting the segment. You can make it simpler by taking an entire sector of the circle (for which you need to find its center) and dividing it into a segment and some triangle. Further, Ssegm = Ssect − Streug, in turn Ssect = 0.5. p. R, here p is the length of the arc, and the area of the equilateral triangle enclosed between the radii R is not difficult to calculate: S = 0.5. a. ha, where a is the length of the base, ha is the height drawn to it. All these values can be obtained using a ruler.

Calculation of the area of a room with several levels

Do you think such rooms don’t exist? It’s completely in vain, a house built on a slope may well have ledges in its layout, for example, so a living room or kitchen can be divided into zones. However, it is not at all necessary to look at the floor, because the ceiling can also consist of several tiers in the most ordinary typical room. Let's say you need to buy paint to paint it. Of course, in general, the areas of the ceiling and floor are equal, but in places where there is a difference in heights, the vertical slopes also have some quadrature. And even taking into account a 10% reserve for purchased materials, they may not be enough. Therefore, we count.

If your levels have a simple shape, with rectangular elements, no difficulties will arise. It is enough to measure the height of the vertical sections with a ruler, find their length and use the formula S = a. b, determine the area with which the quadrature is summed horizontal surfaces. If the edge of the ledge overhangs a lower platform in the form of a cornice, summing the measurements of each tier is not enough, since it will turn out that the underside of the overhanging part is not taken into account. For laying parquet or tiling, these places will not play a special role, but when painting, “white spots” may remain. So in this situation, you should measure the hidden areas with a ruler.

It is better to take measurements with a tape measure or other device closer to the base, since the walls may have a slight curvature, which will give a certain error in the result.

It is most difficult to calculate the area of a room if there are ledges of round or more complex shape. In this case, you need to accurately measure each arc along the edge, either in short sections, or all at once using a tape measure and using someone else's help. Then, having found the radii and splitting the surfaces into separate geometric shapes, use the above formulas and find the area of each ledge. As for the vertical sections, they were also mentioned above; there is no difference between the straight version and the curved one if the perimeter is known.

Starting any project, you need to know how to calculate the area of a room. This knowledge will help you choose the right amount of materials, as well as correctly calculate the dimensions. Such knowledge is also necessary when you need to check the area indicated in the documents.

Our review will help you remember school knowledge and will tell you how to apply them in practice. In addition, you can use a special calculator.

Important information! When performing calculations for a room with projections, columns and niches, it is necessary to take into account their location and configuration.

How to calculate the area of a triangle

Let's figure out how to calculate the area of a triangle. If indoors irregular shape there is an element in the form right angle, then you can apply the following formula:

S=(a*b)/2;

There are other calculation options. To calculate the area of a triangle, you can first determine the quadrature of the rectangle, and then calculate the area of the triangular angle. Then the value of the triangular part is subtracted from the squaring of the rectangle.

If there is no right angle, then you can use Heron’s formula:

S=√p(p-a)(p-b)(p-c);

At the same time a, b, c represent the sides of the triangle, and r– semi-perimeter. To find out, all sides should be summed up and then divided by 2.

To calculate the area of a given figure, you can multiply the length of the base by the height drawn from this base, and then divide the result by 2.

How to find the area of a rectangle

Often there are rooms that look like a rectangle. To calculate the area of a rectangle online calculator is considered the best option. But simple calculations can be done independently. There should be no protruding parts. Measure the width and length. Entries must be made in meters.

To calculate the area of a rectangle, you need to multiply the obtained values. After the decimal point, you can leave only two digits and round the rest.

The question often arises of how to calculate the area of a rectangle if there are niches. In this case, the space is divided into several figures, and they are counted separately. There is another formula for calculating area. In this case, the perimeter of the room must be multiplied by the height. To calculate the perimeter, you need to add the length and width, and then multiply them by two.

How to calculate the area of a trapezoid

To calculate the area of a trapezoid, it is important to know the lengths of two parallel sides, as well as the height. In this case, the height is the perpendicular between the sides.

Here's a formula you can use:

S=1/2(A+B)*h;

It is worth considering that nothing will change depending on the angles of the sides. But it is recommended to measure the height in several places. This approach will ensure that the two sides are parallel.

Knowledge of this formula will also be useful when calculating the areas of rooms with polygonal configurations. For example, an unusual space can be divided into a rectangle and a trapezoid.

There is also a special calculator for calculating rectangular and trapezoidal rooms. In this case, the difference is that the rectangle will have the same lengths. If necessary, adjustments can be made to existing protrusions and niches.

To determine the perimeter, you need to measure the lengths of the four sides and then add them up.

How to calculate the area of a circle

Sometimes it is necessary to calculate the area of a circle, since there may be separate areas of rounded configurations in the room. Such knowledge will also be useful when calculating arched door or window openings. Let's look at shapes based on a circle. The most common are segments, quarter circles or semicircles.

Such calculations are necessary if there is a bay window or a combination of a balcony and a room. In this case, the value of the protruding circle is first determined, and then the resulting indicator is added to the rest of the area.

To calculate the area of a circle, use the following formula:

S=πR²/2,

π equals 3.14. A R² is the radius of the circle squared.

Correct calculation of sector and segment area

A special formula for the area of a sector of a circle is included in the calculator for calculations. This formula looks like this:

S= R²*arcsin(c/2R)-0.25*C*√(4 R²-C²);

How to calculate the area of a room: calculation method by floor

You can calculate the floor area. This procedure consists of the following steps. First of all, it is necessary to clear the walls of the room. It is better to take measurements in an empty room. If the room is rectangular, then you can multiply the two sides. In reality, the sides may differ slightly, which is why it is important to measure all sides. In some cases, the room may not be configured correctly. In this situation, the entire space is divided into separate rectangles. In this case, you can draw a diagram with all dimensions. Then the area of individual plots is calculated. By the way, the room will not necessarily consist only of rectangles. It can contain triangles and even circles.

If you don't know how to count square meters rooms, you can use a special calculator. When calculating dimensions, it is not necessary to observe all dimensions down to the centimeter. Rounding of values is often used. Sometimes it is necessary to take into account various recesses and protrusions in the walls.

When making calculations, it is important to take into account their purpose. If you need to know the values for installation, then you can ignore the space occupied by heavy furniture.

There are options when used indoors different levels floor. In such a situation, it is also necessary to divide the room into separate zones. You should not take measurements on the wall, as it may have a curved surface.

It is difficult to determine the area based on the floor, which has various protrusions in the form of waves or semicircles.

For your information! If the room is L-shaped, then in addition to two rectangular figures there is also a triangle. To determine its area, you can multiply one leg by the other.

How to calculate wall area

To determine the area of the walls, you need to know how to calculate the perimeter of the room. Determining the area is often required to purchase all kinds of finishing materials. In addition to the length and width of the room, you will need to find out the height of the room, as well as the dimensions of the door and window openings.

When making calculations, it is worth considering that the height of the ceilings even in the same room can vary, especially if. The values of all walls are calculated separately, and then window and door openings are subtracted from them.

Exact values can be identified using a calculator for calculating the area of the walls of a room. Sometimes it is necessary to determine the volume of a room. In such a situation, it is necessary to multiply three values: the length, width and height of the room. This indicator is measured in cubic meters.

If the room has multi-level zoning, then the following calculations can be made:

measure all sections of the walls. It is recommended to take measurements closer to the ceiling;
calculate area indicators by floor;
on each vertical section it is necessary to measure the length and height, and then multiply these values;
add the indicators to the gender value.

Each room has optimal parameters that can be taken into account when planning a construction site. The minimum residential area is 8 square meters. m. Room general purpose, such as a hall or living room can have an area of 14 to 25 square meters. m. The minimum room height is 240 cm. If the ceiling is more than three meters, then such a space is more difficult to heat. The kitchen must have an area of at least 6 square meters. m.

Correct calculation of the area of the room is a guarantee of high-quality implementation. This approach will minimize the cost of purchasing materials.

Features of calculation

To find out the necessary data, you will have to apply a formula. The calculation is carried out taking into account the shape of the room and the presence of additional structures in it: loggias, niches, arches, lintels, dressing rooms.

The square footage of a room is not only the floor area. Therefore, when posing the question of how to calculate the square footage of a room, you need to start from the upcoming work.

So, when plastering, the S of the walls and ceiling is calculated, and for tiling the kitchen, you will need to calculate the area of the floor and the surface of the walls to a height of 1.0-1.5 m. Difficulties may arise during the operation if the design of the room is complex: there are beams, niches or alcoves, especially if they are located near window openings.

It would be a mistake to think that the S of the floor and the S of the ceiling are equal. In the attic, for example, the roof slopes hang overhead, forming a so-called hipped ceiling. It is immediately noticeable that the square footage of the floor covering will be larger. Therefore, when starting repairs in the under-roof room, the area of each surface is calculated separately.

Calculation of the square footage of a rectangular room

In a standard room, the floor is always equal and is calculated using the formula for a rectangle S=AxB.

When covering with plasterboard panels, wallpapering, plastering, painting walls and/or ceilings, tiling and other types of repair work that involve leveling and finishing wall coverings, it is necessary to calculate the area.

All calculations are based on the perimeter and height of the room. Having measured them using a tape measure, substitute them into the formula:

S=РхН, where H is the height of the room, P is the perimeter. Formula P=2(A+B), where A and B are indicators of the length of adjacent walls.

Don't forget about window and door openings that are not covered by finishing. Their area must be subtracted from the total.

Important! Remember that for door and arched structures, the formula for a circle segment or semicircle is additionally used.

How to get the measurement result

Srooms= AxB (A - length; B - width).

*width is multiplied by height, after which a number is obtained that reflects the area of the room in m2.

Application of the formula in practice

Problems shouldn't arise if you know how to calculate the square footage of a room. Try to understand the features of calculating the area of a room for wallpapering in more detail, according to the example.

Often, upon completion of repair work, excess material remains. Or at the end of pasting it turned out that there was not enough wallpaper canvas. When planning the finishing, do not forget about the accurate and correct calculation of the area of the room. This way you will save yourself from inconvenient situations during the wallpapering process.

How to determine how much wallpaper is needed?

It all depends on the perimeter of the room and the width of the roll. Having this data in a notebook, calculating the cubic capacity is not difficult. When working with such material, take into account its pattern.

The easiest way is to paste over a wall with sections with a simple image: the canvases do not have to be adjusted. If you purchased rolls with complex geometric patterns, get ready that the material consumption will be greater, because the pieces will have to be cut so that the elements of different cuts fit together to form a single whole.

Important! Regardless of the texture or style of the fabric, always add 2-3 centimeters to the allowance under the baseboards.

Counting wallpaper: how to figure it out?

Let's look at an example. With a perimeter of 12 m and a standard roll width of 53 centimeters, 23 strips of wallpaper will be needed to cover the walls.

Important! When gluing with an overlap, do not forget to take into account the allowances.

If the ceiling height in the room is 2.7 m, add at least 5 cm to the allowance. This gives the length of 1 canvas - 2.75 m. With the standard length of the material in a roll - 10.05 m, 3 whole strips come out of one package. To calculate the number of rolls, divide 23 by 3 and get the number of packages required for finishing - 7.54, that is, you will have to purchase 8 rolls of wallpaper.

Bathroom tiling: how many tiles will you need?

We will analyze the calculation of the required amount of material using an example. Craftsmen use a proven method for calculating the volume of consumables for finishing a bathroom.

To do this, measure the walls and carry out a calculation using a formula to calculate the square footage of the bathroom. Here, as when calculating the required amount of wallpaper, door and window openings are subtracted from the total area.

Let's look at an example. So, having received a number of 21 square meters, find the required number of tiles. First, the area of 1 ceramic product is calculated, with a size of 0.3 x 0.2 we get 0.06 m 2.

S bathroom /S product =n, where n is the number of tiles.

21/0.06=350 pcs. The stock when laying products is 10% of the required number. For example, 35 pieces. As a result, it turns out that 385 whole tile squares will be needed to tidy the bathroom.

Important! The amount of floor covering is determined according to the same scheme.

Using a simple formula, you can independently determine how much finishing material, adhesive mixture, and screed will be needed to carry out repairs in any room of the house. It is convenient and simple, because there is no need to hire specialists to carry out such simple work.

Wall area is a value that is used in cost calculations when performing plastering, painting and wallpapering, as well as in material calculations. Although it would seem that it is considered quite simple, some customers have difficulty with the calculations.

1. Calculation of area for a rectangular room

The most common room shape is rectangular. There are four walls, on one of the walls there is a window, on one of the walls there is a door. That is, to calculate the total area of the walls in a room, you need to calculate the area of each wall separately and then add it up.

Consider a room with a floor area of 28 m2 and dimensions of 7 by 4 meters with one door and one window (see Fig. 1):

Fig.1 Room

The area of the wall without windows and doors (see Fig. 2) is calculated as the length of the wall multiplied by the height:

rice. 2. Wall area without windows and doors.

IN in this case we get:

Wall area = 7 * 2.7 = 18.9 m2

The area of the wall where the door is located is calculated as the area of the wall minus the area of the door (see Fig. 3):

rice. 3. Wall area excluding the door.

In this case we get:

Wall area = 4 * 2.7 - 1 * 2.1 = 8.7 m2

The area of the wall where the window is located is calculated similarly (see Fig. 4):

Fig.4. Wall area excluding windows.

In this case we get:

Wall area = 4 * 2.7 - 0.9 * 1.4 = 9.54 m2

So, we calculated the area of each wall in the room. Let's add them up:

Total wall area in the room= 18.9 + 18.9 + 8.7 + 9.54 = 56.04 m2

A wall with an area of 18.9 m2 is counted twice, since there are two such walls in the room.

2. Calculation of wall area based on floor area

Sometimes there are cases when the area of the walls needs to be known approximately, or the room itself is of non-standard shape, then you can use the ratio:

Wall area = (floor area) times (room height)

For example, for a room with an area of 15 square meters and a height of 2.7 meters, the wall area will be equal to:

15 * 2.7 = 40.5 m2

This method is implemented in our calculator for calculating the cost of wallpapering

3. Calculation of the wall area around the perimeter of the room

For those who remember the school geometry course,

Wall area = (Room perimeter) times (room height) minus window area minus door area