Rebar calculator – Rebar Calculator

Online reinforcement calculator. Quickly calculate the number, length and weight of reinforcing bars for foundations, slabs, columns and walls.

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Reinforcement calculation

Calculate the required number and weight of reinforcing bars for concrete structures

About the rebar calculator

The online reinforcement calculator will help you calculate the required number and weight of reinforcing bars for concrete structures - slabs, foundations, columns, floors and walls. Specify the dimensions of the structure, the mesh spacing and the diameter of the reinforcement - the tool will instantly calculate the total length, weight and approximate number of rods.

The calculator uses standard formulas for calculating reinforcement in accordance with GOST and building codes. The calculation takes into account the mesh pitch, the diameter of the reinforcing bars, the number of layers of reinforcement and the overlap of the bars when connecting. This allows you to obtain accurate results for the design of reinforcement of any concrete structure.

Examples of reinforcement calculations

Let's look at practical examples of calculating the quantity and weight of reinforcement for various structures:

Example 1: Reinforcement for a strip foundation

Strip foundation 10×0.5×0.6 m with mesh 200×200 mm

Входные данные:

Length: 10 m Width: 0.5 m Height: 0.6 m Grid pitch: 200 mm (0.2 m) Reinforcement diameter: 12 mm Layers: 2

Расчёт:

Longitudinal bars: (10/0.2 + 1) × 2 = 51 × 2 = 102 bars Longitudinal length: 102 × 0.5 = 51 m Cross bars: (0.5/0.2 + 1) × 2 = 4 × 2 = 8 bars Cross length: 8 × 10 = 80 m Total length: 51 + 80 = 131 m Weight (Ø12): 131 × 0.888 = 116.3 kg

Результат:

131 m of reinforcement, weight 116.3 kg

Тип:

Strip foundation

Two layers for the top and bottom reinforcement chords

Example 2: Reinforcement for a 6x4 m floor slab

Monolithic floor slab with mesh 150×150 mm

Входные данные:

Length: 6 m Width: 4 m Height: 0.2 m Grid pitch: 150 mm (0.15 m) Reinforcement diameter: 10 mm Layers: 2

Расчёт:

Rods by length: (6/0.15 + 1) × 2 = 41 × 2 = 82 rods Length by length: 82 × 4 = 328 m Rods width: (4/0.15 + 1) × 2 = 28 × 2 = 56 rods Length by width: 56 × 6 = 336 m Total length: 328 + 336 = 664 m Weight (Ø10): 664 × 0.617 = 409.7 kg

Результат:

664 m of reinforcement, weight 409.7 kg

Тип:

Floor slab

Two layers provide bending resistance in both directions

Example 3: Reinforcement of a monolithic wall

Wall 3×2.5×0.3 m with vertical and horizontal reinforcement

Входные данные:

Length: 3 m Width: 2.5 m Height: 0.3 m Grid pitch: 200 mm (0.2 m) Reinforcement diameter: 8 mm Layers: 1

Расчёт:

Vertical bars: (3/0.2 + 1) = 16 bars Vertical length: 16 × 2.5 = 40 m Horizontal bars: (2.5/0.2 + 1) = 14 bars Horizontal length: 14 × 3 = 42 m Total length: 40 + 42 = 82 m Weight (Ø8): 82 × 0.395 = 32.4 kg

Результат:

82 m of reinforcement, weight 32.4 kg

Тип:

Monolithic wall

One layer is sufficient for a thin wall

Example 4: Reinforcement for a column 400×400 mm

Square column 3 m high with longitudinal and transverse reinforcement

Входные данные:

Section: 400×400 mm Height: 3 m Clamp pitch: 150 mm (0.15 m) Longitudinal diameter: 16 mm Clamp diameter: 8 mm Rods: 4 longitudinal

Расчёт:

Longitudinal rods: 4 pcs Longitudinal length: 4 × 3 = 12 m Longitudinal weight (Ø16): 12 × 1.58 = 19.0 kg Number of clamps: (3/0.15 + 1) = 21 clamps Length of one clamp: 4 × 0.35 = 1.4 m Clamp length: 21 × 1.4 = 29.4 m Weight of clamps (Ø8): 29.4 × 0.395 = 11.6 kg Total weight: 19.0 + 11.6 = 30.6 kg

Результат:

41.4 m of reinforcement, weight 30.6 kg

Тип:

Column

Clamps provide transverse reinforcement

Example 5: Reinforcement of a slab foundation 8x8 m

Slab foundation with two-layer mesh 200×200 mm

Входные данные:

Length: 8 m Width: 8 m Height: 0.4 m Grid pitch: 200 mm (0.2 m) Reinforcement diameter: 14 mm Layers: 2

Расчёт:

Rods by length: (8/0.2 + 1) × 2 = 41 × 2 = 82 rods Length by length: 82 × 8 = 656 m Rods width: (8/0.2 + 1) × 2 = 41 × 2 = 82 rods Length by width: 82 × 8 = 656 m Total length: 656 + 656 = 1312 m Weight (Ø14): 1312 × 1.21 = 1587.5 kg

Результат:

1312 m of reinforcement, weight 1587.5 kg

Тип:

Slab foundation

A large area requires a significant amount of reinforcement

Example 6: Reinforcement for grillage for columns

Grillage 12×1×0.5 m with mesh 180×180 mm

Входные данные:

Length: 12 m Width: 1 m Height: 0.5 m Grid pitch: 180 mm (0.18 m) Reinforcement diameter: 12 mm Layers: 2

Расчёт:

Longitudinal bars: (12/0.18 + 1) × 2 = 68 × 2 = 136 bars Longitudinal length: 136 × 1 = 136 m Cross bars: (1/0.18 + 1) × 2 = 7 × 2 = 14 bars Cross length: 14 × 12 = 168 m Total length: 136 + 168 = 304 m Weight (Ø12): 304 × 0.888 = 270.0 kg

Результат:

304 m of reinforcement, weight 270.0 kg

Тип:

Grillage

The grillage requires strong reinforcement to distribute the load

How to calculate reinforcement

The calculator uses standard formulas for calculating reinforcement:

Формулы расчёта:

  • Length = (Structure size / Grid pitch + 1) × Number of layers
  • Weight = Length × Weight per meter (according to GOST)
  • Quantity = Length / Rod Length

Benefits of the calculator

Our reinforcement calculator provides many benefits for accurate reinforcement calculations.

Accuracy of calculations

The calculator uses proven formulas in accordance with GOST and building codes, taking into account all parameters: structure dimensions, mesh pitch, reinforcement diameter and number of layers for the most accurate results.

Saving money

Correct calculation of the amount of reinforcement helps to accurately determine the required material and avoid overspending, which significantly reduces the cost of the project.

Project planning

Knowing in advance the required quantity and weight of reinforcement, you will be able to properly plan purchases and logistics, avoiding mistakes during construction.

Ease of use

A simple interface and quick calculations allow you to get all the necessary data in a few seconds without complex calculations and formulas.

Tips for reinforcing concrete structures

To properly reinforce concrete structures, it is important to consider many factors that affect strength and durability.

Selection and installation

  • Always choose the diameter of the reinforcement based on the load: for foundations Ø10-16 mm, for slabs Ø8-12 mm, for walls Ø6-10 mm, for columns Ø12-20 mm
  • Optimal grid pitch: for foundations 15-25 cm, for slabs 10-20 cm, for walls 15-30 cm. A smaller pitch increases strength, but also consumption of reinforcement
  • For slabs and floors, use at least 2 layers of reinforcement (top and bottom); for thin walls, one layer is sufficient

Calculation of parameters

  • Take into account the overlap of the rods when connecting - it should be at least 30-50 times the diameter of the reinforcement to ensure the strength of the connection
  • Provide a protective layer of concrete 2-5 cm thick between the reinforcement and the surface to protect against corrosion
  • To anchor reinforcement, use a length of at least 10-15 diameters, this will ensure reliable fastening of the rods

Flow optimization

  • Use standard mesh spacing (150, 200, 250 mm) - this simplifies installation and reduces reinforcement consumption
  • Choose standard reinforcement diameters (8, 10, 12, 14, 16, 18, 20 mm) - they are always on sale and have the correct weight according to GOST
  • Optimize rod lengths - use standard 11.7m or 12m lengths to minimize cutting waste

Frequently Asked Questions

How to calculate the amount of reinforcement for a foundation?

Enter the foundation dimensions (length, width, height), grid spacing and reinforcement diameter. The calculator will calculate the number of rods: for longitudinal (Length/Pitch + 1) × Number of layers, for transverse (Width/Pitch + 1) × Number of layers. Then multiplied by the length of the rods to obtain the total length and mass.

How to choose the diameter of the reinforcement for the foundation?

The diameter of the reinforcement for the foundation is selected based on the load and type of foundation. For a strip foundation of a private house, reinforcement Ø10-12 mm is used, for a slab foundation - Ø12-16 mm, for a pile foundation - Ø10-14 mm. For heavy loads, use reinforcement Ø14-16 mm or more.

Is it possible to calculate the weight of reinforcement by diameter?

Yes, the calculator automatically calculates the weight of reinforcement according to GOST depending on the diameter. Reinforcement meter weight: Ø8 mm - 0.395 kg/m, Ø10 mm - 0.617 kg/m, Ø12 mm - 0.888 kg/m, Ø14 mm - 1.21 kg/m, Ø16 mm - 1.58 kg/m, Ø18 mm - 2.0 kg/m, Ø20 mm - 2.47 kg/m.

What is the reinforcement mesh pitch and how to choose it?

Mesh spacing is the distance between reinforcing bars in a mesh. For the foundation, the optimal step is 15-25 cm, for floor slabs 10-20 cm, for walls 15-30 cm. A smaller step increases the strength and consumption of reinforcement, a larger step reduces strength. Standard steps: 100, 150, 200, 250, 300 mm.

Is the calculator suitable for strip foundations?

Yes, the calculator is ideal for calculating strip foundation reinforcement. Select the “foundation” structure type, enter the length, width and height of the foundation, specify the grid spacing and the diameter of the reinforcement. The calculator will calculate the number of longitudinal and transverse rods for the upper and lower chords.

How to calculate reinforcement for a floor slab?

For the floor slab, enter the length and width of the slab, the grid spacing (usually 150-200 mm) and the diameter of the reinforcement (usually 10-12 mm). Specify 2 layers for two-layer reinforcement. The calculator will calculate the bars in both directions and the total amount of reinforcement.

How much reinforcement is needed per cube of concrete?

The amount of reinforcement per cube of concrete depends on the type of structure: for foundations 50-150 kg/m³, for floor slabs 80-120 kg/m³, for walls 40-80 kg/m³, for columns 150-250 kg/m³. The exact quantity is calculated by the calculator based on the specific dimensions and grid spacing.

How to calculate the number of reinforcement bars?

The number of rods is calculated by the formula: (Structure size / Grid pitch + 1) × Number of layers. For example, for a slab 6 m long with a pitch of 200 mm and 2 layers: (6/0.2 + 1) × 2 = 31 × 2 = 62 rods along the length. Then multiplied by the width for the total length.

What diameter of reinforcement should I use for the slab?

For floor slabs, reinforcement with a diameter of 8-12 mm is usually used. For thin slabs (up to 15 cm) Ø8-10 mm is sufficient, for thick slabs (15-25 cm) Ø10-12 mm is used, for very thick slabs (more than 25 cm) Ø12-14 mm or more is used. The choice depends on the load on the floor.

How to calculate the overlap of reinforcement?

The overlap of the reinforcement when connecting the rods should be at least 30-50 times the diameter of the reinforcement. For example, for reinforcement Ø12 mm the overlap is 360-600 mm. The overlap is taken into account when calculating the total length of the reinforcement - the overlap length is added to each length of the rod.

Is it possible to calculate reinforcement for a column?

Yes, the calculator supports the calculation of reinforcement for columns. Enter the column section dimensions (length and width), height, stirrup spacing, longitudinal reinforcement diameter, and stirrup diameter. The calculator will calculate the number of longitudinal bars, the number of clamps and the total weight of the reinforcement.

How to calculate reinforcement for a monolithic wall?

For a monolithic wall, enter the length, width (thickness) and height of the wall, grid spacing (usually 200-300 mm) and reinforcement diameter (usually 8-10 mm). The calculator will calculate vertical and horizontal rods. For thin walls one layer is enough, for thick walls two layers are enough.

How much reinforcement is needed for a slab foundation?

For a slab foundation, the amount of reinforcement depends on the area of ​​the slab, grid spacing and diameter. For example, for a slab 8x8 m with a pitch of 200 mm and reinforcement Ø12 mm, about 650-750 kg of reinforcement will be required with two-layer reinforcement. The calculator will accurately calculate the required amount.

How to choose reinforcement class A400 or A500?

The reinforcement class is selected based on the load: A400 (old marking A-III) is suitable for most structures, A500 (modern marking) has higher strength and is recommended for critical structures. The calculator calculates the quantity regardless of the class, but the weight is the same for the same diameters.

How to calculate the protective layer of concrete for reinforcement?

The protective layer of concrete should be: for foundations in the ground - at least 4 cm, for foundations not in the ground - 3 cm, for walls and slabs up to 25 cm - 2 cm, for slabs and walls over 25 cm - 2.5 cm. The calculator does not take into account the protective layer in calculating the length, but it must be taken into account during installation.

Can reinforcing mesh be used instead of individual bars?

Yes, reinforcing mesh can be used instead of individual bars. The mesh simplifies installation and ensures precise pitch. The calculator calculates the equivalent number of rods for a mesh with a given pitch. When using mesh, consider standard roll and sheet sizes.

How to calculate the cost of fittings?

The cost of fittings is calculated as the product of weight and price per kilogram. Enter the price of the reinforcement (usually 50-80 ₽/kg depending on the diameter and region), the calculator will show the total cost. For an accurate calculation, also take into account the cost of delivery and cutting of reinforcement.

What is the reinforcement pitch for the foundation of a house?

For a strip foundation of a private house, the optimal reinforcement mesh pitch is 150-200 mm. For a slab foundation, the pitch is usually 200-250 mm. A smaller pitch (100-150 mm) is used for heavy loads or on soft soils. The calculator will help you choose the optimal step for your case.

How to calculate reinforcement for a grillage?

For the grillage, enter the length, width and height, grid pitch (usually 150-200 mm) and reinforcement diameter (usually 12-14 mm). The grillage requires two layers of reinforcement, so specify 2 layers. The calculator will calculate the longitudinal and transverse rods for the upper and lower chords.

Is it possible to calculate the consumption of fittings for the entire house?

Yes, you can calculate the reinforcement for each element (foundation, walls, floors, columns) separately and summarize the results. The calculator saves results that can be exported to Excel to summarize and analyze the total reinforcement consumption for the entire project.

How to calculate the number of clamps for a column?

The number of stirrups for a column is calculated as (Column height / Stirrup spacing + 1). For example, for a column 3 m high with a stirrup pitch of 150 mm: (3/0.15 + 1) = 21 stirrups. The length of one clamp is calculated as the perimeter of the column, taking into account the protective layer.

What is the amount of reinforcement per square meter of slab?

The amount of reinforcement per m² of slab depends on the grid pitch and diameter. With a pitch of 200 mm and reinforcement Ø10 mm: about 5 m/m² or 3-3.5 kg/m² with two-layer reinforcement. With a step of 150 mm, the flow rate increases to 6-7 m/m² or 4-4.5 kg/m². The calculator will accurately calculate for your parameters.

How to calculate reinforcement for a floor with ribs?

For a ribbed floor, calculate the reinforcement for the slab separately, then for the ribs. The ribs use reinforcement of a larger diameter (12-16 mm) with a smaller pitch. The calculator allows you to calculate each item separately, then add the results to get the total quantity.

What is the weight of the reinforcement per meter of diameter?

Weight of one meter of reinforcement according to GOST: Ø6 mm - 0.222 kg/m, Ø8 mm - 0.395 kg/m, Ø10 mm - 0.617 kg/m, Ø12 mm - 0.888 kg/m, Ø14 mm - 1.21 kg/m, Ø16 mm - 1.58 kg/m, Ø18 mm - 2.0 kg/m, Ø20 mm - 2.47 kg/m, Ø22 mm - 2.98 kg/m, Ø25 mm - 3.85 kg/m. The calculator uses these values ​​automatically.

How to calculate the minimum amount of reinforcement for a foundation?

According to the standards, the minimum amount of reinforcement for the foundation must be at least 0.1% of the cross-sectional area for longitudinal reinforcement. For a strip foundation with a width of 400 mm and a height of 600 mm, the minimum reinforcement area is: 0.001 × 400 × 600 = 240 mm². This is approximately 4 rods Ø10 mm or 2 rods Ø12 mm per meter of length.

Is it possible to use composite reinforcement instead of steel?

Yes, composite (fiberglass or basalt-plastic) reinforcement can be used instead of steel. It has less weight (3-4 times lighter) and is not subject to corrosion. When calculating, take other strengths and elasticities into account. The calculator calculates the number of rods the same, but the weight needs to be recalculated.

How to calculate reinforcement for a monolithic staircase?

For a monolithic staircase, calculate the reinforcement for flights and landings separately. In flights, reinforcement Ø10-12 mm is used with a pitch of 150-200 mm, in platforms - similarly. The calculator allows you to calculate each element (length and width of the flight, dimensions of the landings) and obtain the total amount of reinforcement for the stairs.

How much reinforcement for a pile foundation?

For one pile with a diameter of 300 mm and a height of 2 m with reinforcement Ø12 mm, you will need 4-6 longitudinal rods 2 m long (8-12 m total) and clamps with a pitch of 150-200 mm (about 13-17 clamps). Total weight for one pile: about 15-25 kg. Multiply by the number of piles to obtain the total consumption.

How to calculate reinforcement for floor beams?

For a floor beam, enter the length, width and height of the beam, the pitch of the transverse reinforcement (usually 150-200 mm) and the diameters of the longitudinal (12-16 mm) and transverse (6-8 mm) reinforcement. The calculator will calculate longitudinal rods for the lower and upper chords and transverse rods (clamps) for the entire beam.

How to take into account reinforcement waste when calculating?

When calculating, take into account reinforcement waste of 5-10% for scraps and non-standard lengths. The calculator shows the exact quantity required to which the stock needs to be added. The standard length of the reinforcement is 11.7-12 m; when calculating, take into account the optimization of the length of the rods to minimize waste.

How to calculate reinforcement for a foundation with a basement?

For a foundation with a basement, calculate the reinforcement for the external and internal walls separately, then for the basement floor slab. Use the same reinforcement parameters (pitch, diameter) for all elements. The calculator allows you to calculate each element separately, then sum the results to obtain the total consumption.

How much reinforcement is needed to reinforce the corners of the foundation?

In the corners of the foundation, additional reinforcement with reinforcement is required due to stress concentration. Use L-shaped or U-shaped elements made of reinforcement with a diameter equal to the main reinforcement, with a length of at least 40 diameters in each direction. 20-30% of additional reinforcement from the main one is added to the corner reinforcement.