What is the Density of Mild Steel? Everything You Need to Know
June 17, 2026

Mild steel is an alloy with low carbon content, typically less than 0.1%. It combines the durability of stainless steel with workability, making it versatile for various applications. The density of mild steel material is a key property that determines its usage in industries such as construction, manufacturing, and household goods.
Understanding the Density of Mild Steel
The density of mild steel defines its mass per unit volume and typically ranges between 7,750 kg/m³ and 8,050 kg/m³, depending on the alloy composition. The density of mild steel in kg/m3 is crucial for determining its applications in structural and manufacturing fields, ensuring the material can withstand specific loads while maintaining integrity.
Key Density Metrics for Mild Steel: kg/m³ and kg/mm³

- Mild Steel in kg/m³: The standard density of mild steel in kg/m3 is approximately 7,850 kg/m³, widely used in engineering calculations to estimate weight and material requirements.
- Mild Steel in g/cm³: Converting the density of mild steel in kg/m3 to grams per cubic centimetre (g/cm³) results in approximately 7.85 g/cm³. This unit is often used in precise engineering contexts.
- Mild Steel in kg/mm³: For finer calculations, the density of mild steel in kg/mm3 is 7.85 x 10-3 kg/mm³, suitable for small-scale precision measurements.
- Mild Steel in lb/in³: In imperial units, the density of mild steel material is approximately 0.284 lb/in³, commonly used in industries utilising imperial measurements.
How to Calculate the Density of Mild Steel
Understanding the Formula
Density is calculated using the formula:
Density=Mass/Volume
This formula determines the density of mild steel material, where:
- Mass is the weight of the object (typically in kilograms)
- Volume is the space occupied by the object (in cubic meters)
Measure the Mass
Accurately measure the mass of the mild steel sample using a calibrated scale. For example, assume the mass is 5 kg.
Determine the Volume
Calculate the volume of the sample. For regularly shaped objects, use geometric formulas; for irregular shapes, use displacement methods.
Assume the volume is 0.000637 m³.
Convert Units if Necessary
Ensure the units of mass and volume align. For example, if the mass is in kilograms and the volume is in cubic meters, no conversion is needed. For the density of mild steel in kg/mm3, adjust the units accordingly. For this example:
- Mass is in kilograms (kg)
- Volume is in cubic meters (m³)
No conversion is required to maintain SI units.
For density in kg/mm³, convert:
1m³=1×109 /mm³
Volume=0.000637m³= 637,000/mm³
Perform the Calculation
Divide the mass by the volume (Density=Volume/Mass) to determine the density of mild steel material:
Example: Density=5 kg/0.000637m³
Final Formula with Values
The generalised formula with substituted values is:
Density=5/0.0006375 ≈7,849.76kg/m³
If converted to cubic millimetres:
Density=5 kg/637,000 mm³ ≈7.85×10−6 kg/mm³
Interpret the Results
Compare the calculated density of mild steel with standard values to verify the material’s properties.
Applications of Mild Steel Based on its Density

Construction and Structural Applications
The density of mild steel in kg/m3 makes it ideal for building frames and reinforced conrete.
Manufacturing and Industrial Uses
The density of mild steel material ensures it is suitable for machinery, automotive components, and industrial equipment. Its properties enable precise fabrication and efficient performance.
Everyday Uses
In daily life, the density of mild carbon steel contributes to the durability and premium feel of kitchenware, appliances, and decorative items.
What Are the Different Grades of Mild Steel?
Mild steel is available in various grades tailored for specific applications. Here is a basic overview:
| Grade | Composition | Applications |
| S275JR | Low carbon content | Structural applications such as bridges, buildings, and general construction |
| S355JR | Low carbon content | High-strength structural applications, including bridges, overhead cranes, and buildings |
| Q195 | Yield strength of 195 MPa | Similar properties and applications as EN standards like S275JR |
| Q215 | Yield strength of 215 MPa | Similar properties and applications as EN standards like S275JR |
| Q235B | Yield strength of 235 MPa | Similar properties and applications as EN standards like S275JR |
| Q345B | Yield strength of 345 MPa | Similar properties and applications as EN standards like S355JR |
The “Q” grades refer to Chinese steel standards, where the number indicates the yield strength in megapascals (MPa). These grades have comparable properties and applications to the EN standards mentioned.





