Round-Steel Weight and Cost Calculator
Enter the bar dimensions to instantly calculate the exact weight and material cost. Our calculator supports round, square, and flat bars, and allows calculation of weight and cost for multiple pieces simultaneously.
Result
0.000 kg
Weight = π × (Diameter/2)² × Length × Density
Material Density Table - Reference Data
The table below presents detailed density values for various materials used for manufacturing rods/bars and utilized in our calculator. Precise density values are key to obtaining accurate bar weight calculation results:
| Material | Density (kg/m³) | Characteristics |
|---|---|---|
| Plain Steel (carbon) | 7850 | Most popular construction material, high strength, good weldability |
| Stainless Steel | 7930 | Increased corrosion resistance, used in aggressive environments |
| Aluminum | 2700 | Lightweight metal, good corrosion resistance, high strength-to-weight ratio |
| Copper | 8930 | Excellent electrical and thermal conductivity, used in installations |
| Brass | 8500 | Copper and zinc alloy, good machinability, corrosion resistance |
| Lead | 11340 | Very heavy metal, used as radiation shielding |
| Titanium | 4500 | Lightweight, very strong, exceptional resistance to corrosion and high temperatures |
The above density values are standard values for pure materials or typical alloys used in industry. In practice, depending on the exact alloy composition, heat treatment, or material quality, the density may vary slightly (usually by ±1-2%).
How is bar weight calculated? - Calculation Methodology
Our calculator uses precise mathematical and physical formulas to calculate the weight of bars of different shapes. Depending on the selected bar type, different formulas are used:
Round Bars
The weight of a round bar is calculated based on the formula:
Weight = π × (Diameter/2)² × Length × Density
where:
- π (pi) - mathematical constant approx. 3.14159
- Diameter - diameter of the bar [m]
- Length - length of the bar [m]
- Density - material density [kg/m³]
Dimensions provided in millimeters are automatically converted to meters during calculations.
Square Bars
The weight of a square bar is calculated based on the formula:
Weight = Side² × Length × Density
where:
- Side - side length of the square cross-section [m]
- Length - length of the bar [m]
- Density - material density [kg/m³]
Flat Bars
The weight of a flat bar is calculated based on the formula:
Weight = Width × Thickness × Length × Density
where:
- Width - width of the bar cross-section [m]
- Thickness - thickness of the bar cross-section [m]
- Length - length of the bar [m]
- Density - material density [kg/m³]
Calculation Examples
Example 1: Round Steel Bar
Data:
- Diameter: 20 mm (0.02 m)
- Length: 1000 mm (1 m)
- Material: plain steel (7850 kg/m³)
Calculation:
Weight = π × (0.02/2)² × 1 × 7850
Weight = 3.14159 × 0.0001 × 1 × 7850
Weight = 2.466 kg
Example 2: Square Aluminum Bar
Data:
- Side: 15 mm (0.015 m)
- Length: 2000 mm (2 m)
- Material: aluminum (2700 kg/m³)
Calculation:
Weight = 0.015² × 2 × 2700
Weight = 0.000225 × 2 × 2700
Weight = 1.215 kg
Applications of Bars - Industries and Use Cases
Metal bars are extremely versatile construction materials used in many industrial and construction sectors. Below are the most important applications for different types of bars:
Round Bars
Round bars find wide application in the following fields:
- Construction - reinforcements, anchors, threaded rods
- Mechanical Engineering - shafts, axles, rotating elements
- Metalwork - handrails, railings, decorative elements
- Furniture production - frames, structural elements
- Automotive industry - elements of power transmission systems
Square Bars
Square bars are commonly used in:
- Steel structures - frames, supports, mountings
- Artistic metalwork - decorative elements, grates
- Furniture industry - table legs, frames, reinforcements
- Fences and railings - spans, posts
- Industrial halls - structural and support elements
Flat Bars
Flat bars find application in:
- Steel structures - connectors, reinforcements, stiffeners
- Metalwork - hinges, fittings, mountings
- Mechanical Engineering - brackets, bases
- Construction - anchors, ties, clamps
- Fences and gates - decorative elements, spans
Main industry sectors using bars
Construction
Reinforcement of concrete structures, ties, anchors, support structures, railings, fences
Mechanical Engineering
Shafts, axles, pins, guides, drive elements, components of machines and devices
Architecture and Furnishings
Handrails, railings, furniture, decorative elements, accessories, frames
Frequently Asked Questions (FAQ) - Comprehensive Information
We have gathered answers to the most frequently asked questions about calculating bar weight and using our calculator. If you don't find the answer to your question here, please contact us directly.
The most common standard bar lengths available on the market are:
- 3000 mm (3 meters)
- 6000 mm (6 meters)
- 12000 mm (12 meters)
Shorter lengths are usually available as cut pieces. For large orders, many warehouses also offer cutting bars to size according to customer needs, which can help optimize transport costs and reduce waste.
To convert dimensions from inches to millimeters, multiply the value in inches by 25.4. For example:
- 1/4 inch diameter bar = 6.35 mm
- 1/2 inch diameter bar = 12.7 mm
- 1 inch diameter bar = 25.4 mm
- 2 inch diameter bar = 50.8 mm
In industrial practice, especially in an international context, it is always worth confirming whether dimensions are in the metric or imperial system to avoid errors in calculations and orders.
The main difference between a bar and a tube lies in their construction:
- Bar - is a solid element, full throughout its cross-section (e.g., a round bar is simply a cylinder)
- Tube - is a hollow element, having a hole along its entire length
This fundamental difference significantly impacts the properties of these elements:
- Tubes are lighter than bars of the same outer diameter
- Tubes have a better stiffness-to-weight ratio for bending loads
- Bars have greater strength against torsion and axial compression
- Tubes can additionally serve as conduits for transporting media
Note: Round Bars vs. Tubes
Do not confuse solid round bars with tubes, which are hollow elements.
To calculate the weight of tubes, use the pipe and profile calculator, which takes into account both the outer and inner diameter.
To calculate the weight of a bar with a non-standard cross-section, you need to:
- Calculate the cross-sectional area in m²
- Multiply the cross-sectional area by the length of the bar in m
- Multiply the resulting volume by the material density in kg/m³
For example, for a bar with a trapezoidal cross-section:
- Cross-sectional area = ((long base + short base) × height) / 2
- Volume = cross-sectional area × length
- Weight = volume × material density
For very complex shapes, it may be necessary to use advanced calculation methods or CAD software to accurately determine the volume.
Dimensional tolerances for bars depend on their production method, material, and applicable standards in a given country. Typical dimensional tolerances are:
- Cold-drawn bars: typically ±0.05 mm to ±0.2 mm, depending on the diameter
- Hot-rolled bars: usually ±0.3 mm to ±1.0 mm
- Ground bars: tolerances can be much smaller, even down to ±0.01 mm
Exact tolerance values are specified by technical standards, such as:
- BS EN 10060 - for hot-rolled round bars
- BS EN 10059 - for hot-rolled square bars
- BS EN 10058 - for hot-rolled flat bars
- BS EN 10278 - for drawn or ground steel bars
For precise weight calculations for large quantities of bars, it is worth considering these tolerances, especially for bars with large diameters, where even small dimensional deviations can affect the final weight.
Practical Application Examples of Bar Weight Calculations
Discover practical examples of using bar weight calculations in various industrial and construction applications:
Example 1: Reinforcement of a concrete structure
Scenario: A construction company needs to calculate the weight of reinforcing bars for a foundation slab measuring 12×15 m.
Required data:
- Ribbed round bars with a diameter of 12 mm
- Bar spacing: 15 cm in both directions
- Bar lengths: 12 m and 15 m
- Material: reinforcing steel (7850 kg/m³)
Calculations:
- Number of 12 m bars: 15 m / 0.15 m = 100 pieces
- Number of 15 m bars: 12 m / 0.15 m = 80 pieces
- Weight of one 12 m bar: π × (0.012/2)² × 12 × 7850 = 10.62 kg
- Weight of one 15 m bar: π × (0.012/2)² × 15 × 7850 = 13.27 kg
- Total weight: (100 × 10.62) + (80 × 13.27) = 1062 + 1061.6 = 2123.6 kg
Application: Thanks to these calculations, the company can accurately plan material purchases, transport reinforcement to the construction site, and determine the costs for this part of the investment.
Example 2: Balustrade production
Scenario: A metal workshop received an order for 20 balcony railings, each 3 m long.
Required data:
- Frame made of 20×20 mm square bar
- Infill with 12 mm diameter round bars (15 pieces per railing)
- Railing height: 1.1 m
- Material: plain steel (7850 kg/m³)
Calculations:
- Length of square bar per railing: 2 × 3 m + 2 × 1.1 m = 8.2 m
- Weight of square bar: 0.02² × 8.2 × 7850 = 25.76 kg
- Length of round bar per railing: 15 × 1.1 m = 16.5 m
- Weight of round bar: π × (0.012/2)² × 16.5 × 7850 = 14.6 kg
- Weight of one railing: 25.76 + 14.6 = 40.36 kg
- Total weight: 20 × 40.36 = 807.2 kg
Application: Calculations allow determining material cost, planning the production process, and transporting the finished railings to the client.