# Steel Weight Calculator

URL: https://speedycalculator.com/calculators/construction/steel-weight/
Last updated: 2026-10-25

> The steel weight calculator finds the weight of plates, bars, tubes, angles and sheets from their dimensions and the density of the material, per piece and in total, plus the weight per metre or foot.

## Inputs

- Material
- Custom density (kg/m³, lb/ft³, g/cm³, lb/yd³)
- Shape
- Width / diameter / side / leg (mm, in, cm)
- Height (rectangular tube) (mm, in, cm)
- Thickness / wall (mm, in, cm)
- Sheet area (m², ft², yd²)
- Length (m, ft, cm, in, yd)
- Number of pieces

## Results

- Cross-section area
- Volume of one piece
- Weight of one piece
- Total weight
- Weight per metre

## Formula

```
Weight = cross-section area × length × density × pieces
Tube area = π/4 × (D² − (D − 2t)²)
Angle area = t × (2a − t)
```

## Explanation

Steel stock is ordered by size but priced, shipped and lifted by weight. This calculator finds the weight of steel plate, flat bar, round and square bar, hex bar, pipe and tube, angle and sheet in carbon, mild, stainless, tool steel and cast or wrought iron, for one piece or a whole cut list.

### How to use the Steel Weight Calculator

- **Material**
- **Custom density**
- **Shape**
- **Width / diameter / side / leg**
- **Height (rectangular tube)**
- **Thickness / wall**
- **Sheet area**
- **Length**
- **Number of pieces**
- Every result field is editable: type into **Weight of one piece** or any other result and **Length** plus every other field update to match.

Results update as you type, and every field accepts the units shown in its menu.

### How it works

The calculator works out the cross-sectional area of the shape you choose, multiplies it by the length to get the volume, then by the density of the material to get the weight. Tubes subtract the hollow core; angles count both legs once.

### Densities used

Materialkg/m³lb/in³lb/ft³Carbon steel7,8500.2836490.1Mild steel7,8700.2843491.3Stainless steel 3047,9300.2865495.1Stainless steel 3168,0000.2890499.4Tool steel7,7150.2787481.6Wrought iron7,7500.2800483.8Cast iron7,2000.2601449.5

### Good to know

Rule of thumb: steel plate weighs 7.85 kg per m² per mm of thickness, or 40.8 lb per ft² per inch.

### Tips for an accurate estimate

- Sketch the job and split irregular areas into rectangles, circles and triangles before you measure.
- Add a waste allowance – typically 5–10% for simple layouts and 15–20% for diagonal, curved or heavily cut work.
- Check the coverage or yield printed on the product, because sizes and densities vary between manufacturers.
- Buy all units of a finished material (tile, brick, siding) from the same batch so colours match, and keep a few spares for repairs.
- Confirm local prices – quarry, lumber and steel prices vary widely by region and season.

### Common mistakes to avoid

- Ordering exactly the calculated amount with no allowance for breakage, offcuts and settlement.
- Forgetting to subtract doors, windows and other openings – or subtracting small ones that still need cutting around.
- Confusing US short tons (2,000 lb) with metric tonnes (1,000 kg) when comparing quotes.

### Inputs explained

FieldWhat to enterMaterialChoose one: Carbon steel, Mild steel, Stainless steel 304, Stainless steel 316 …Custom densityUnits: kg/m³, lb/ft³, g/cm³, lb/yd³ShapeChoose one: Plate / flat bar (width × thickness), Round bar (diameter), Square bar (side), Hexagonal bar (across flats) …Width / diameter / side / legUnits: mm, in, cmHeight (rectangular tube)Units: mm, in, cmThickness / wallUnits: mm, in, cmSheet areaUnits: m², ft², yd²LengthUnits: m, ft, cm, in, ydNumber of piecesA number

## Worked example

Inputs — Material: Carbon steel; Custom density: 7,850 kg/m³; Shape: Plate / flat bar (width × thickness); Width / diameter / side / leg: 100 mm; Height (rectangular tube): 50 mm; Thickness / wall: 10 mm; Sheet area: 1 m²; Length: 1 m; Number of pieces: 1.

Results — Cross-section area = 1,000 mm²; Volume of one piece = 1,000 cm³; Weight of one piece = 7.85 kg; **Total weight = 7.85 kg**; Weight per metre = 7.85 kg/m.

## FAQ

**How much does a steel plate weigh per square foot?**
About 40.8 lb per ft² for each inch of thickness (≈ 7.85 kg/m² per mm).

**What is the weight of a 1-inch round steel bar?**
About 2.67 lb per foot (3.97 kg/m).

**Is stainless steel heavier than mild steel?**
Slightly – 304 stainless is about 7,930 kg/m³ versus 7,850 for carbon steel.

**What formula does the Steel Weight Calculator use?**
Weight = cross-section area × length × density × pieces.


## Sources

- [The Engineering ToolBox – Metals and alloys densities](https://www.engineeringtoolbox.com/metal-alloys-densities-d_50.html)