Updated Steel & Structure

Steel Beam Calculator

Estimate steel beam load capacity, deflection, required section modulus, stiffness, weight and total steel tonnage with this multi-mode steel beam calculator.

Bending Capacity & Loads Deflection & Service Limits Beam Size, Weight & Tonnage

Steel Beam Capacity, Deflection, Size & Weight Estimator

Calculation Mode

Length Units Spans and overall beam lengths use these units.

Section Property Units Section modulus, inertia and weight per length follow this convention.

Steel Strength Units Yield strength is entered in ksi or MPa. Modulus of elasticity can be entered as ksi or GPa.

Beam Span (center-to-center)

Load Type

Yield Strength F_y Enter in ksi (e.g. 36, 50) or MPa (e.g. 250, 355) according to the strength units above.

Section Modulus S_x US: in³ from steel tables. Metric: cm³ from section tables.

Strength Reduction / Safety Factor φ Use 0.9 as a typical bending strength factor for planning-level capacity.

Factored Design Load (optional)

Optional design load for a quick capacity check against φM_n.

Beam Span (center-to-center)

Load Type

Service Load Value

Use unfactored service loads for deflection checks.

Modulus of Elasticity E In ksi if strength units are ksi (typical steel E ≈ 29,000 ksi), or in GPa if using MPa (typical steel E ≈ 200 GPa).

Moment of Inertia I_x US: in⁴ from section tables. Metric: cm⁴ from section tables.

Deflection Limit Common serviceability limits for floors, roofs and architectural finishes.

Beam Length

Weight per Unit Length

Use values from steel shape tables (e.g. lb/ft or kg/m).

Number of Beams

Price per Unit Weight (optional)

Enter a rough price per lb or per kg to estimate steel beam cost.

Beam Span (center-to-center)

Load Type

Factored Design Load

Factored design load used for bending strength checks.

Service Load for Deflection

Unfactored service load used for deflection requirements.

Yield Strength F_y

Modulus of Elasticity E In ksi for ksi units, or in GPa for MPa units.

Strength Reduction / Safety Factor φ

Deflection Limit

Steel Beam Calculator

Steel Beam Capacity, Deflection, Size & Weight Estimator

Geometry & Span Details

Capacity, Loads & Deflection

Section Properties, Weight & Size

Planning Notes & Limitations

Steel Beam Calculator

Steel Beam Capacity, Deflection, Size & Weight Estimator

Geometry & Span Details

Capacity, Loads & Deflection

Section Properties, Weight & Size

Planning Notes & Limitations

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