Concrete Beam Design (ACI 318-19M)

Calculate factored load, maximum moment, required tensile steel area, and design checks for a rectangular reinforced concrete beam using ACI 318-19M provisions.

Beam Inputs

📊 Calculation Results

Enter inputs to compute ACI 318-19M design results.

Load, Shear, Moment and Deflection Diagrams

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Loading Diagram q(x) [kN/m]

Shear Force V(x) [kN]

Bending Moment M(x) [kN·m]

Deflection δ(x) [mm]

Design Basis

Strength design per ACI 318-19M. Factored load: wu = 1.2wD + 1.6wL. Maximum moment for simply supported beam with uniform load: Mu = wuL²/8.

  • β1: 0.85 for f'c ≤ 28 MPa, reduce 0.05 per 7 MPa to 0.65 minimum
  • ρb: 0.85·β1·(f'c/fy)·(600/(600 + fy)) (SI; εcu·Es ≈ 600 MPa)
  • ρmin (SI): max(0.25√f'c/fy, 1.4/fy)
  • φ: 0.65 → 0.90 by tensile strain limits (ACI 318-19M)
  • Mn: As·fy·(d − a/2), a = As·fy/(0.85·f'c·b)