Concrete Beam Calculator — m, m³, rebar
How to use this calculator
Select beam type (rectangular, T-beam with slab flange, or L-beam edge). Enter width, total depth, and span length using mm/cm/m dropdown selectors. For T/L-beams, add flange width and slab thickness. Results update instantly.
Cost — pick ready-mix per m³, 50 kg bags, or 25 kg bags. Select currency.
Reinforcement — bottom tension bars, top compression bars, and stirrups with variable spacing per EC2 §9.2.2. Min/max reinforcement ratios shown.
Labor — rate per beam, per m³, or flat price.
Saved Calculations
| Time | Type | Size | Qty | Vol m³ | Cost | Rebar | Rebar | Labor | Total |
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How to Calculate Concrete for Beams (Metric)
This calculator estimates concrete volume in cubic meters, bags (25 kg and 50 kg), reinforcement (main bars and stirrups per EN 1992-1-1), and cost for rectangular, T-beam, and L-beam sections. Enter dimensions in mm, cm, or m. For T/L-beams, specify flange width and slab thickness.
Reinforcement per EN 1992-1-1 (Eurocode 2)
Bottom tension bars carry the bending moment. Top bars provide compression/continuity capacity. Stirrups resist shear per §6.2 — spacing must not exceed 0.75d in critical zones and follows EC2 §9.2.2 rules. Minimum tension steel: 0.26×(f_ctm/f_yk)×b_w×d but not less than 0.0013×b_w×d. Lap splices at 40db per §8.7.
Formulas
Rectangular: V = b × h × L. T-beam: V = b_w × h × L + (b_f − b_w) × h_f × L. L-beam: stem + one-sided flange. Concrete density: 2,400 kg/m³. Stirrup perimeter: 2×(b_w − 2c) + 2×(h − 2c) + hooks.
FAQ
What is the typical beam depth? Rule of thumb: span/16 to span/12. A 6 m span typically needs 375–500 mm deep beam. T-beam or rectangular? T-beams are monolithic with the slab, giving larger compression zone. Use T-beam for interior beams, L-beam for edge beams.
