Inputs
Results
Example data table
Sample spans and loads for quick testing.
| Section | L | w | wₛ[a,b] | P@a | Units |
|---|---|---|---|---|---|
| W200x46 | 4000 | 10 | 6 [500,1500] | — | SI |
| W250x67 | 5000 | 0 | — | 30000@2500 | SI |
| W310x60 | 6000 | 6 | 0 [0,0] | 15000@3000 | SI |
Formulas used
Simply supported
- UDL (full): \(M_{max} = wL^2/8\), \(V_{max} = wL/2\)
- Point at midspan: \(M_{max} = PL/4\), \(V_{max} = P/2\)
- Point at a: \(M_{max} \approx Pab/L\), \(b=L-a\)
- Deflection (UDL): \(\delta_{max} = 5wL^4/(384EI)\)
- Deflection (midspan P): \(\delta_{max} = PL^3/(48EI)\)
- Partial UDL [a,b]: Use resultant \(W=w(b-a)\) at centroid \((a+b)/2\) for reactions.
Cantilever & fixed-fixed
- Cantilever UDL: \(M_{max} = wL^2/2\), \(V_{max} = wL\)
- Cantilever tip P: \(M_{max} = PL\), \(V_{max} = P\)
- Fixed-fixed UDL: \(M_{max} = wL^2/12\) (at supports)
- Fixed-fixed mid P: \(M_{max} = PL/8\)
- Deflection (cantilever UDL): \(\delta = wL^4/(8EI)\)
- Deflection (fixed-fixed UDL): \(\delta = wL^4/(384EI)\)
Bending stress \( \sigma = M/S_x \). Utilization = \( \sigma/F_y \). Superposition and standard envelopes are used; detailed envelopes may vary slightly.
How to use this calculator
- Select units and support condition.
- Pick a section preset or enter properties manually.
- Enter full-span UDL, optional self‑weight, and any partial UDL.
- Add one or more point loads with positions along the span.
- Click Calculate; review reactions, bending, shear, deflection, checks.
- Export CSV or PDF, or save and reload a scenario as JSON.
Reference data for steel beam load calculations
1) Typical material properties
| Grade | Elastic modulus E | Yield strength Fy | Notes |
|---|---|---|---|
| S235 / ASTM A36 | 200,000 MPa | 235–250 MPa | Common mild structural steel |
| S275 | 200,000 MPa | 275 MPa | Higher yield than S235 |
| S355 / ASTM A992 | 200,000 MPa | 345–355 MPa | Frequent for W‑shapes |
2) Common deflection limits (serviceability)
- L/240 – general purpose framing, moderate finishes.
- L/360 – floors with brittle finishes or tighter comfort.
- L/480 – sensitive finishes, long-span members, stricter performance.
3) Wide‑flange quick reference (presets shown)
| Section | Ix | Sx | Zx | Units |
|---|---|---|---|---|
| W200x46 | 8.54e8 | 8.54e6 | 9.46e6 | mm⁴ / mm³ |
| W250x67 | 2.03e9 | 1.63e7 | 1.79e7 | mm⁴ / mm³ |
| W310x60 | 2.88e9 | 1.86e7 | 2.06e7 | mm⁴ / mm³ |
| W8x24 | 128 | 32 | 35 | in⁴ / in³ |
| W10x39 | 389 | 78 | 86 | in⁴ / in³ |
| W12x58 | 925 | 154 | 170 | in⁴ / in³ |
4) Unit conversion quick sheet
- Length: 1 in = 25.4 mm
- Force: 1 lbf = 4.448221615 N
- Stress: 1 ksi = 6.894757 MPa
- Ix: 1 in⁴ = 25.4⁴ mm⁴
- Sx, Zx: 1 in³ = 25.4³ mm³
- UDL: 1 lbf/in = 4.448221615/25.4 N/mm
Frequently Asked Questions
1) Which codes or standards does this tool follow?
This tool performs fundamental elastic beam checks. It does not implement a specific national standard. Always verify results against your governing code and local practice before issuing drawings or approving final designs.
2) Can I add multiple point loads and partial distributed loads?
Yes. Use the point-load table to add rows, and the partial uniform load fields for a segment. The calculator combines effects by superposition and reports a reasonable envelope for design screening.
3) Are lateral–torsional buckling or shear buckling checks included?
No. This version evaluates bending stress, shear, and elastic deflection only. Stability checks such as lateral–torsional buckling or web buckling require separate verification according to the applicable design standard.
4) How accurate are the envelopes for off‑center point loads?
For simply supported beams, a general formula \(M \approx Pab/L\) is used, with deflection approximated versus midspan. For fixed‑fixed cases, off‑center loads are estimated conservatively. Use detailed analysis for final member selection near capacity.
5) Which section properties should I enter: Ix, Sx, or Zx?
Enter at least Ix and Sx. Ix is required for deflection; Sx for bending stress. Zx is optional and shown for reference. Use manufacturer or steel manual data to avoid transcription mistakes.
6) Does switching units convert all inputs automatically?
Yes. Lengths, forces, stresses, and section properties are converted between metric and imperial. Preset tables also switch units. Review values after converting units to ensure they match your project conventions.
7) Can I export or share the results with my team?
Yes. Use CSV for spreadsheets or PDF for a quick report. You can also save a JSON scenario to reload later or share as a reproducible configuration with collaborators.