Grade Beam Calculator — m, m³, rebar
How to use this calculator
Enter the number of grade beams, length, width, and depth. A grade beam is a reinforced concrete beam at or near ground level that spans between piers, piles, or footings. Choose units (m, cm, mm) from the dropdown next to each input. Results update instantly.
Cost — pick ready-mix per m³, 50 kg bags, or 25 kg bags. Select your currency below.
Reinforcement — longitudinal bars (top + bottom) plus stirrups spaced per EC2. Lap splices at 40db per EN 1992-1-1 §8.7.
Labor — rate per linear meter, per m³, or flat price.
Saved Calculations
| Time | Beams | Size | Vol m³ | Cost | Rebar m | Rebar | Labor | Total |
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How to Calculate Concrete for Grade Beams (Metric)
A grade beam is a reinforced concrete beam at ground level that connects piers, piles, or column footings. This calculator estimates concrete volume in cubic meters, number of pre-mixed bags (25 kg and 50 kg), total weight in kilograms, reinforcement (longitudinal bars and stirrups), and cost. Enter beam width (typically 30–60 cm), depth (typically 60–90 cm), and span length. Choose the unit (m, cm, or mm) from each dropdown.
Reinforcement per EN 1992-1-1 (Eurocode 2)
Grade beams require top and bottom longitudinal bars (typically Ø12 to Ø20) plus closed stirrups (Ø8 or Ø10) spaced at 0.75d maximum per EC2 §9.2.2. The calculator accounts for lap splices at 40db per EN 1992-1-1 §8.7, concrete cover per exposure class, and cutting waste. Standard bar length is 6 m or 12 m.
Formulas
Volume per beam = Width × Depth × Length. Total volume = Volume per beam × Number of beams × (1 + Waste%). Stirrup perimeter = 2 × (Width − 2 × cover) + 2 × (Depth − 2 × cover). Concrete density: 2 400 kg/m³.
FAQ
What size grade beam do I need? For residential construction, 30×60 cm is common for light loads. For larger spans or heavier loads, use 45×75 cm or 60×90 cm. Always consult a structural engineer for specific requirements.
