HR Plate Weight Calculation
Accurately calculate the weight and cost of Hot Rolled (HR) steel plates for engineering, logistics, and procurement.
mm
cm
m
inches
feet
Enter the length of the plate along the rolling direction.
Please enter a valid positive length.
mm
cm
m
inches
feet
Enter the width of the plate.
Please enter a valid positive width.
mm
cm
inches
Enter the thickness (gauge) of the plate.
Please enter a valid positive thickness.
Number of plates required.
Quantity must be at least 1.
Mild Steel (HR) – 7850 kg/m³
Stainless Steel (304) – 7930 kg/m³
Stainless Steel (316) – 8000 kg/m³
Aluminum – 2700 kg/m³
Copper – 8960 kg/m³
Cast Iron – 7200 kg/m³
Standard density for Hot Rolled Steel is 7850 kg/m³.
per kg
per ton
per lb
Enter price to estimate total cost.
Total Weight
245.31 kg
Weight Per Plate
245.31 kg
Total Area
3.13 m²
Estimated Cost
$208.51
Formula Used: Weight = Length × Width × Thickness × Density
| Parameter | Value |
|---|
Selected Material
Aluminum (Comparison)
Stainless Steel (Comparison)
Chart compares the weight of your dimensions across different materials.
What is HR Plate Weight Calculation?
HR plate weight calculation is the process of determining the theoretical mass of Hot Rolled (HR) steel plates based on their physical dimensions and material density. This calculation is a fundamental step in civil engineering, metal fabrication, logistics planning, and procurement.
Hot Rolled steel is steel that has been roll-pressed at very high temperatures (over 1,700°F), which is above the recrystallization temperature for most steels. Because the steel is easier to form at this temperature, HR plates are commonly used in construction, heavy machinery, and truck frames. Knowing the exact weight is critical for:
- Logistics: Ensuring trucks and shipping containers are not overloaded.
- Cost Estimation: Steel is often sold by weight (per ton or per kg), so accurate weight equals accurate pricing.
- Structural Engineering: Calculating dead loads on structures.
HR Plate Weight Calculation Formula
The core physics behind the calculation is simple: Mass = Volume × Density. However, in the steel industry, we apply specific units to make this practical.
The standard formula used globally is:
Weight (kg) = Length (m) × Width (m) × Thickness (mm) × 7.85
Here is the breakdown of the variables:
| Variable | Meaning | Standard Unit | Typical Range |
|---|---|---|---|
| Length (L) | Longest dimension | Meters (m) | 2m – 12m |
| Width (W) | Shortest dimension | Meters (m) | 1m – 3m |
| Thickness (T) | Gauge of the plate | Millimeters (mm) | 1.6mm – 100mm+ |
| Density (ρ) | Mass per unit volume | kg/m³ | 7850 (Mild Steel) |
Note: If you calculate volume in cubic meters (m³), you multiply by 7850 kg/m³. The simplified formula above (multiplying thickness in mm by 7.85) is a shortcut derived from: (T/1000) × 7850 = T × 7.85.
Practical Examples of HR Plate Weight Calculation
Example 1: Standard Construction Plate
A fabricator needs to order 10 plates of Mild Steel for a baseplate. The dimensions are 2500mm x 1250mm with a thickness of 12mm.
- Convert to Meters: 2.5m (L) × 1.25m (W)
- Volume Calculation: 2.5 × 1.25 × 0.012 = 0.0375 m³ per plate
- Weight Calculation: 0.0375 m³ × 7850 kg/m³ = 294.375 kg per plate
- Total Order Weight: 294.375 × 10 = 2,943.75 kg
Example 2: Cost Estimation
A procurement manager is buying a heavy HR plate (6m x 2m x 25mm). The supplier quotes $900 per metric ton.
- Weight: 6 × 2 × 25 × 7.85 = 2,355 kg
- Convert to Tons: 2,355 kg = 2.355 Metric Tons
- Total Cost: 2.355 tons × $900/ton = $2,119.50
How to Use This HR Plate Weight Calculator
- Enter Dimensions: Input the Length, Width, and Thickness. You can select different units (mm, cm, m, inches) for each field; the calculator handles the conversion automatically.
- Select Material: The default is Mild Steel (7850 kg/m³), which covers most HR plates. If you are using Stainless Steel or Aluminum, change this selection.
- Input Quantity: Enter the total number of plates required for the project.
- Add Price (Optional): If you know the price per kg or per ton, enter it to get an instant cost estimate.
- Analyze Results: Review the Total Weight and Total Area. Use the chart to see how the weight compares to other materials.
Key Factors That Affect HR Plate Weight Results
While the theoretical formula is precise, real-world weights can vary due to several factors:
- Rolling Tolerances: Hot rolling is not as precise as cold rolling. Manufacturers have a "rolling tolerance," meaning a 10mm plate might actually be 10.3mm thick in the center (the "crown"). This can increase actual weight by 3-5%.
- Material Composition: "Steel" is an alloy. High-carbon steel or alloy steels with elements like Tungsten may have slightly higher densities than the standard 7850 kg/m³.
- Scale and Rust: HR plates have a surface layer of mill scale (iron oxide). While negligible for single plates, on a 10,000-ton shipment, scale and surface rust can affect the net weight.
- Shape Irregularities: Plates are often sheared or flame-cut. Rough edges or slightly out-of-square cuts affect the actual volume compared to the theoretical rectangle.
- Coating Weight: If the HR plate has been subsequently galvanized or painted, the weight of the coating (zinc or epoxy) must be added to the base steel weight.
- Temperature: While minor, steel expands with heat. Measurements taken at high temperatures during production will result in different dimensions than when the steel cools to ambient temperature.
Frequently Asked Questions (FAQ)
What is the density of HR steel plate?
The standard density used for Hot Rolled (HR) mild steel is 7850 kg/m³ (or 7.85 g/cm³). This is the industry standard for commercial quality steel.
Does HR plate weigh the same as CR (Cold Rolled) plate?
Theoretically, yes. The density of steel does not change significantly between hot and cold rolling. However, CR plates have tighter dimensional tolerances, so their actual weight is often closer to the theoretical weight than HR plates.
How do I calculate weight in pounds (lbs)?
To calculate in pounds, calculate the volume in cubic inches and multiply by the density of steel in lbs/in³ (approx 0.2836 lbs/in³). Or, simply calculate in kg and multiply by 2.20462.
Why is my actual plate heavier than the calculated weight?
This is usually due to "over-rolling." Mills often roll plates slightly thicker than the nominal gauge to ensure they meet minimum strength requirements, leading to a positive weight tolerance.
Can I use this for checkered (durbar) plates?
Not exactly. Checkered plates have raised patterns for grip. You must add an extra weight factor (usually 2-6 kg/m² depending on the pattern) on top of the base plate thickness calculation.
What is the weight of a 4×8 steel plate?
A standard 4ft x 8ft plate (approx 1219mm x 2438mm) varies by thickness. For 1/4 inch (6.35mm) thickness, it weighs approximately 163 lbs (74 kg).
Is stainless steel heavier than mild steel?
Yes, slightly. 304 Stainless Steel has a density of roughly 7930 kg/m³, making it about 1% heavier than standard mild steel.
How accurate is this calculator for budgeting?
It provides a theoretical weight. For financial budgeting, it is recommended to add a contingency of 3-5% to account for rolling tolerances and waste.