TryBuildCalcGrade Beam Cost CalculatorGrade beam cost estimator
Calculate concrete, steel, and shuttering quantity for a grade (plinth) beam tying the foundation together.
🕒 Last updated: August 12, 2026
Grade Beam Dimensions
ℹ️Sum of every grade beam run in the building — around the perimeter and any internal ties — not a single span.
ℹ️Commonly matches the wall thickness above it.
Concrete
Reinforcement
ℹ️Commonly 150-200 mm centre-to-centre for a plinth beam.
Lap Splices
ℹ️Commonly 40-50× diameter depending on the applicable code and concrete grade — a grade beam's total run almost always exceeds one 12m stock length.
Shuttering
Cost
Please enter a valid shuttering rate
Enter the total plinth beam run length, beam size, and reinforcement details to calculate concrete, steel, and shuttering quantities.
Looking for the verification checklist, reference tables, tips, or common mistakes?See the complete Grade Beam Calculator.
Grade beam cost estimate
This page pre-selects cost estimation, so concrete cost (rate × final volume), steel cost (rate × total weight, including lap splice material), and shuttering cost (rate × contact area, if included) are all shown together with a combined total.
Edit the rates above to match your local supplier and labour pricing — the underlying concrete, steel, and shuttering quantities are calculated exactly the same way as the main calculator.
- Concrete cost = final wastage-adjusted volume × your entered rate per m³ (or per cft).
- Steel cost = total reinforcement weight (including lap splice material, if enabled) × your entered rate per kg.
- Shuttering cost (if included) = side contact area × your entered rate per m² (or per sq ft).
How Is the Grade Beam Quantity Calculated?
The calculation happens in three parts — concrete volume, steel reinforcement (with optional lap splices), and shuttering area — then an optional cost estimate on top.
Step 1 — Concrete Volume
Wet Volume = Total Length × Width × Depth
Dry Volume = Wet Volume × 1.54
Cement Bags = Cement Volume ÷ 0.0347 m³/bag (50 kg bags)
Dry volume accounts for the voids between aggregate particles that disappear once the concrete is mixed and compacted. The dry volume is split into cement, sand, and aggregate using the selected mix ratio, and wastage is applied once to the final quantities.
Step 2 — Steel Reinforcement
Effective Length = Total Length − (2 × Concrete Cover)
Splices per Bar (if laps included) = ROUND UP(Effective Length ÷ 12 m) − 1
Cutting Length per Bar = Effective Length + (Splices × Lap Multiplier × Diameter)
Stirrups = ROUND UP(Total Length ÷ Spacing) + 1
Unit Weight (kg/m) = Diameter² ÷ 162
Top and bottom bars run the full length minus end cover; when lap splices are enabled, this calculator estimates how many 12m stock-length splices each bar needs and adds the extra material each splice requires. Stirrups are closed loops sized to the concrete section minus cover, with a hook allowance added at both ends.
Step 3 — Shuttering Area (Optional)
Side Area = 2 × Depth × Total Length
Only the two vertical side faces need formwork — a grade beam typically bears on PCC/blinding at the bottom, the same reasoning used for footing and raft edge shuttering on this site.
Worked Example
This example walks through your current inputs above, using the same steps as the Formula section.
Enter valid inputs above to generate the worked example.
Disclaimer: This calculator provides approximate results for planning and estimation purposes only. Actual requirements may vary based on site conditions, materials, workmanship, and local building regulations. Always consult a qualified engineer, architect, or construction professional before making final decisions.