Steel Calculator: Planning to use steel in your House or any big projects? Maybe you're building something big like a house, or something small like a gate. Before buying steel, it's a good idea to know how much you really need. This simple Steel Calculator helps you estimate weight and volume quickly so you can order the correct amount.
This calculator gives clear answers fast so you can plan purchases and cuts efficiently. It saves time and money by showing weight per piece, weight per meter, and total weight for the quantity you enter. It also helps convert units correctly (mm ↔ m ↔ inches) and explains the formulas used so you know how results are computed.
The tool asks for three kinds of inputs: material type (which determines density), shape (round, pipe, plate, etc.), and size (diameter, width, height, thickness, length). It converts the dimensions into a cross-sectional area, multiplies by length to get volume, and then multiplies by density to get weight. Results are shown in kg (per piece) and kg/m (weight per meter) and also as total weight for the quantity you enter.
The calculator uses standard geometry formulas. Here are the main ones so you can double-check or calculate manually if needed.
Typical densities used by the calculator: Mild Steel ≈ 7850 kg/m³, Stainless Steel ≈ 8030 kg/m³, Carbon Steel ≈ 7840 kg/m³. You can enter a custom density if you work with a special alloy.
Use the table below for quick reference. Values assume mild steel at 7850 kg/m³. Small rounding differences may occur with other calculators depending on density chosen.
Quick lookup keywords (for convenience): steel weight per meter, 8mm steel weight per meter, 10mm steel weight per meter, 12mm steel weight per meter, 16mm steel weight per meter, 20mm steel weight per meter, 25mm steel weight per meter, 20 mm steel weight per meter, tor steel weight per meter.
| Diameter / Size | Formula | Weight (kg/m) | Use Case |
|---|---|---|---|
| 8 mm | π×(8²)/4×7850×1e-6 |
0.395 kg/m | Light rebars, small framework |
| 10 mm | π×(10²)/4×7850×1e-6 |
0.617 kg/m | Medium rebars, railings |
| 12 mm | π×(12²)/4×7850×1e-6 |
0.888 kg/m | Beams, small columns |
| 16 mm | π×(16²)/4×7850×1e-6 |
1.579 kg/m | Main reinforcement, moderate load bars |
| 20 mm | π×(20²)/4×7850×1e-6 |
2.467 kg/m | Heavy reinforcement, structural bars |
| 25 mm | π×(25²)/4×7850×1e-6 |
3.855 kg/m | Large sections, heavy frames |
The most common formula used for round bars (and the formula used by the calculator) is: Weight (kg/m) = (π × D² / 4) × Density × 1e-6. Use density 7850 for mild steel to match the table above.
The table above shows the value for 8mm steel weight per meter as 0.395 kg/m (mild steel). Use the calculator to get exact values for custom density or different lengths.
The table above shows the value for 10mm steel weight per meter as 0.617 kg/m (mild steel). Enter 10 mm diameter in the calculator for per-piece and total weights.
The table above shows the value for 12mm steel weight per meter as 0.888 kg/m. For different alloys change the density in the calculator.
The table above shows the value for 16mm steel weight per meter as 1.579 kg/m (mild steel).
The table above shows the value for 20mm steel weight per meter as 2.467 kg/m (mild steel). Note the variant 20 mm steel weight per meter (with a space) is the same numeric value and is included here for clarity.
The table above shows the value for 25mm steel weight per meter as 3.855 kg/m (mild steel).
If your users search for tor steel weight per meter (regional/TMT term), they will find the same formula and values — tor/TMT bar weights follow the same geometric formula; use the table above or the calculator for exact kg/m values.
Example 1: Round bar, D = 20 mm, Length = 1000 mm (1 m), Density = 7850 kg/m³.
Step 1: Weight(kg/m) = (π × D² / 4) × Density × 1e-6. Substituting: (π × 400 / 4) × 7850 × 1e-6 = (π × 100) × 7850 × 1e-6 ≈ 2.467 kg/m. So a single 1 m bar weighs ≈ 2.467 kg.
Example 2: Pipe, OD = 50 mm, Wall thickness = 3 mm, Length = 2 m, Density = 7850 kg/m³.
Step 1: Outer radius Ro = 25 mm; inner radius Ri = 22 mm. Area = π × (25² − 22²) = π × 141 ≈ 443.1 mm². Volume = 443.1 × 2000 = 886,200 mm³ = 0.0008862 m³. Weight = 0.0008862 × 7850 ≈ 6.95 kg for the 2 m pipe (≈ 3.475 kg/m).
Q: What information do I need to calculate steel weight?
A: You need three things: the shape (round, pipe, plate, etc.), the dimensions (diameter, width, height, thickness, length), and the material density (defaults are provided). The calculator lets you choose common shapes and default densities to get results fast.
Q: How accurate is the calculator?
A: Accuracy depends on input quality. The calculator uses precise geometric formulas and standard density values; small deviations can happen if density varies between batches or if measurements are rough. Expect accuracy within a small percent when using correct density and precise measurements.
Q: Why might results differ slightly between calculators?
A: Differences usually come from different density assumptions (e.g., 7850 vs 7870 kg/m³) or rounding methods. Use a custom density if you want exact matching with a supplier.
Q: Can I use this for stainless steel and other alloys?
A: Yes. The calculator includes common density presets and supports custom density input for special alloys.
Q: Should I enter length in mm or meters?
A: Both work; mm is recommended for small pieces to keep precision. For long lengths you can use meters — just ensure the unit selector (if present) matches what you enter.
Q: How do I estimate extra material for cutting loss?
A: Add a buffer of 5–10% depending on how much cutting and rework you expect. Small projects may need ~5%, heavy fabrication 8–10%.
Q: What is the difference between weight per piece and weight per meter?
A: Weight per meter is normalized for ordering/pricing (kg/m). Weight per piece is how heavy each item is given its length. Both are useful: kg/m for purchase rates, piece weight for handling and transport.
Q: Is this tool suitable for structural design?
A: This is a material estimation tool and does not replace structural engineering calculations. Consult a qualified structural engineer for load-bearing designs and code compliance.
