Rebar Spacing Calculator
Calculate required steel area and rebar spacing for reinforced concrete sections under bending moment.
How to Use the Rebar Spacing Calculator
- Enter the factored bending moment in kN·m.
- Enter the rebar diameter in mm.
- Enter the steel yield strength in MPa.
- Enter the effective depth of the section in mm.
- Click Calculate for required area and spacing.
Casos de Uso
- •Slab reinforcement design.
- •Beam bottom steel layout.
- •Checking existing reinforcement adequacy.
- •Reinforced concrete coursework.
Fórmula
As = Mu / (φ × fy × j × d), spacing = Ab / As × 1000 mm. φ=0.9, j=0.875.
Preguntas Frecuentes
What is the effective depth?
The effective depth (d) is the distance from the compression face to the centroid of the tension reinforcement.
What yield strength should I use?
Common values: 250 MPa (mild steel), 415 MPa (Fe415), 500 MPa (Fe500/Grade 60).
Is maximum spacing limited?
Yes — the result is capped at 300 mm, which is the typical code maximum for slabs.