Check axial strength, radii, slenderness, and moment capacity. Use equal or unequal angle dimensions easily. Save results, compare examples, and understand each calculation step.
All dimensions are in millimeters. Stress values are in MPa. Effective length factor and safety factor are unitless.
| Case | Leg A | Leg B | Thickness | Length | Fy | K | SF | Area | Tension | Compression | Mx |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 1 | 50 | 50 | 5 | 1,000 | 250 | 1.00 | 1.67 | 475.00 | 71.11 | 47.80 | 0.47 |
| 2 | 75 | 75 | 6 | 1,500 | 250 | 1.00 | 1.67 | 864.00 | 129.34 | 87.41 | 1.30 |
| 3 | 100 | 75 | 8 | 2,000 | 250 | 1.00 | 1.67 | 1,336.00 | 200.00 | 103.14 | 1.76 |
Area: A = t(a + b - t)
Centroid: the calculator uses a composite section method. Two rectangles are added. One overlapping square is removed.
Moments of inertia: Ix, Iy, and Ixy are found from the composite section and shifted to the centroid with the parallel axis rule.
Principal inertias: Imax and Imin come from the standard principal axis equation using Ix, Iy, and Ixy.
Radius of gyration: r = √(I / A)
Slenderness ratio: KL/r = (K × L) / rmin
Johnson formula: Fcr = Fy[1 - Fy(KL/r)² / (4π²E)]
Euler formula: Fcr = π²E / (KL/r)²
Tension capacity: Pt = A × Fy / SF
Compression capacity: Pc = A × Fcr / SF
Approximate bending capacity: M = S × Fy / SF
This tool switches between Johnson and Euler behavior by using the transition slenderness Cc = √(2π²E / Fy).
Angle iron is a common structural shape. It is used in frames, braces, shelves, trailers, towers, and support members. Its L-shaped profile gives useful stiffness with modest weight. Strength depends on area, thickness, leg sizes, length, material grade, and the loading pattern. A long thin member can fail by buckling before the steel reaches yield stress. A short member usually carries more direct load.
This calculator gives quick section checks. It estimates cross-sectional area, centroid, moments of inertia, radii of gyration, slenderness ratio, tensile capacity, compressive capacity, and approximate bending capacity. It handles equal and unequal angles. It also applies a user supplied effective length factor and safety factor. These outputs are useful for early design review, comparison studies, classroom work, and fabrication planning.
Area controls basic tension strength. The centroid affects how the section balances around each axis. Moments of inertia describe resistance to bending. The smallest principal inertia often governs compression behavior because buckling follows the weakest direction. Radius of gyration links inertia with area. Slenderness ratio then shows whether a member acts like a short column or a long column.
The values are practical estimates, not final certified design values. Real structures may include holes, weld effects, end conditions, eccentric loads, residual stresses, and local code rules. Connection details also matter. Use the results to screen options fast. Then verify important work with the proper structural standard, detailed drawings, and professional review when needed.
This tool is helpful when you compare several angle sizes, check a trial member, study buckling trends, or prepare teaching examples. It saves time and keeps the main formulas visible. Because the result appears above the form, you can review strength numbers immediately and then refine the inputs for another check.
The section model treats the angle as two rectangles with an overlapping square removed. That method gives clear geometric properties and works well for many checks. The compression formula switches between Johnson and Euler behavior from slenderness. This is helpful for education and first-pass sizing. It should not replace a full code based design package for final project approval.
It estimates angle iron area, inertia, slenderness, tension capacity, compression capacity, and approximate bending capacity from user inputs.
Yes. Enter different values for Leg A and Leg B. The calculator handles both equal and unequal angle sections.
Compression members can buckle. A long angle may fail from instability before the material reaches full yield stress.
K adjusts the length for end restraint. Pinned, fixed, and cantilever conditions produce different buckling behavior and different slenderness values.
Use them for quick checks and comparison work. Final structural design should follow the required design standard and connection rules.
Enter dimensions in millimeters, yield strength in MPa, elastic modulus in MPa, and member length in millimeters.
No. It assumes a clean ideal section. Holes, corrosion, welds, and eccentric loading can reduce actual capacity.
The angle geometry becomes invalid if thickness equals or exceeds a leg size. Real angle sections require positive remaining leg lengths.
Important Note: All the Calculators listed in this site are for educational purpose only and we do not guarentee the accuracy of results. Please do consult with other sources as well.