How to Calculate Angle Iron Weight (With Formula & Weight Chart)

Angle irons are one of the most commonly used steel profiles in fabrication, construction, and DIY projects. Knowing how to calculate the weight of an angle iron helps you estimate cost, transportation needs, and structural load capacity. If you work with steel materials, this skill will save you time and money.

Let’s break it down in the simplest way possible.

Understanding What Angle Iron Is

Angle iron (also called L-angle or angle bar) is a steel profile shaped like the letter L. It has two legs that meet at a right angle.

Types of Angle Iron

• Equal Angle Iron – Both legs are the same length (e.g., 50 × 50 × 6mm).

• Unequal Angle Iron – One leg is longer than the other (e.g., 75 × 50 × 6mm).

These dimensions determine how strong and heavy the angle iron will be.

Why Calculating Weight Matters

Understanding the weight of an angle iron is important because:

• Budgeting: Steel is sold by weight.

• Transport: Helps you know the load capacity required.

• Structural Design: Ensures the steel meets engineering requirements.

Knowing the weight avoids guesswork and makes planning easier.

Components Involved in Weight Calculation

Before using the formula, you need these dimensions:

• A: Leg 1 length

• B: Leg 2 length

• Thickness (T): Thickness of the legs

• Length (L): Total length of the angle bar

• Density (ρ): Steel density (depends on material type)

Standard units:

• Lengths in millimeters (mm)

• Length in meters (m)

• Weight in kilograms (kg)

ALSO READ: How to Choose the Right Steel for Your Construction Project in Nigeria

Formula for Equal Angle (A = B)

Formula for Unequal Angle (A ≠ B)

Where:

• A & B = leg lengths (mm)

• T = thickness (mm)

• L = length (m)

• 7.85 = density of steel (g/cm³ converted to kg/m³)

These formulas give the weight of the angle bar in kilograms.

Step-by-Step Calculation Example

Let’s calculate the weight of an equal angle iron with:

• Dimensions: 50 × 50 × 6 mm

• Length: 6 meters

Step 1: Use the formula

Weight=(2A−T)×T×L×7.851000\text{Weight} = \frac{(2A - T) \times T \times L \times 7.85}{1000}Weight=1000(2A−T)×T×L×7.85​

Step 2: Substitute values

=(100−6)×6×6×7.851000= \frac{(100 - 6) \times 6 \times 6 \times 7.85}{1000}=1000(100−6)×6×6×7.85​=94×6×6×7.851000= \frac{94 \times 6 \times 6 \times 7.85}{1000}=100094×6×6×7.85​

Step 3: Calculate

94 × 6 = 564
564 × 6 = 3384
3384 × 7.85 = 26564.4
26564.4 ÷ 1000 = 26.56 kg

So, a 50 × 50 × 6mm angle iron (6 meters long) weighs about 26.56 kg.

Standard Steel Density Values

• Mild steel: 7.85 g/cm³

• Stainless steel: 7.9–8.0 g/cm³

• Galvanized steel: Slightly heavier due to coating

Always use the correct density to avoid inaccurate estimates.

Angle Iron Weight Chart (Common Sizes)

Equal Angle Weight Chart (per meter)

Unequal Angle Weight Chart (per meter)

(Values vary slightly.)

Tools for Quick Angle Iron Weight Calculation

You can avoid manual calculation by using:

• Online steel weight calculators

• Mobile engineering apps

• Steel supplier websites

These tools give instant results for any dimension.

Factors That Affect Weight Accuracy

• Manufacturing tolerances: Slight size variations

• Coatings: Galvanized steel weighs more

• Material type: Stainless vs mild steel

Always add a small margin when ordering steel.

How to Measure Angle Iron Dimensions Correctly

To get accurate results:

• Use a digital caliper or steel measuring tape

• Measure the outer leg lengths

• Measure thickness at multiple points

• Don’t confuse nominal vs actual thickness

Accuracy matters especially for structural use.

Practical Uses of Angle Iron Weight Calculation

You’ll find weight calculation useful in:

• Construction (beams, frames, supports)

• Metal fabrication

• Automotive work

• Furniture making

• DIY welding projects

Correct weight means better planning, cost control, and proper load distribution.

Common Mistakes to Avoid

• Using the wrong density

• Forgetting to convert mm to m

• Measuring inside instead of outside legs

• Not accounting for coating weight

• Mixing up equal and unequal angles

Avoid these and your calculations will always be accurate.

Calculating the weight of angle iron is straightforward once you understand the formula and measurements involved. Whether you’re budgeting, fabricating, or planning a structural project, knowing the exact weight helps you avoid errors and make better decisions.

Use the formula, follow the steps, or quickly refer to the weight chart whenever needed.