Tank or Trench Concrete Calculator
Reviewed by Engr. Talha Tariq | PEC License #: PEC-CIVIL-37815 | Last updated: 2025-10-24
Quickly compute concrete volumes for rectangular and circular tanks and foundation trenches. Enter clear internal dimensions and thicknesses, choose units, and add waste to get ordering values in m³ and yd³ (ft³ available).
Trench volume uses rectangular or trapezoidal prism geometry. Tanks subtract inner void from outer envelope; cover slab is optional.
Step 1 — Choose Units
All dimensions will be interpreted as m.
Adds extra volume to cover spillage, over-excavation, uneven base, etc.
Typical 5–10%
Step 2 — Core Dimensions
Overall trench length.
Typical 3–60 m
Uniform trench width.
Vertical depth of trench.
Typical 0.5–2.0 m
Step 3 — Optional Parameters
Step 4 — Actions
Enter values above and press Calculate to reveal results.
Key Features of Our Free Tank / Trench Concrete Calculator
Trench, Rectangular Tank, and Circular Tank — switch by tabs to match your scope.
Enter all dimensions in meters, centimeters, feet, or inches; conversions are handled for you.
Use Width for rectangular trenches or Top/Bottom Widths for trapezoidal sections.
Rectangular & circular tanks include wall, base, and optional cover slab thicknesses.
Clean, gated results in m³, with quick conversions to yd³ and ft³. Yardage helpers included.
See base slab, walls, and cover slab volumes separately when using tank modes.
Export an A4-friendly summary for records and reset inputs with one click.
Why Choose Our Tank / Trench Calculator?
- Accurate geometry for trenches and tanks with proper unit handling throughout.
- Built-in waste allowance helps avoid shortages during pours.
- Per-mode inputs reduce confusion and keep your workflow fast.
- Tank breakdown (base, walls, cover) supports estimating and approvals.
- Yardage helper (+5% / +10%) mirrors supplier rounding practices.
How to Use the Tank / Trench Concrete Calculator
- Select a Mode: Trench, Rectangular Tank, or Circular Tank.
- Choose one Unit (m, cm, ft, or in). Enter all fields using that unit.
- Provide dimensions:
- Trench: Length, Depth, and either Width (Rectangular) or Top/Bottom Widths (Trapezoidal).
- Rectangular Tank: Inner L×W×H plus Wall, Base, and optional Cover thickness.
- Circular Tank: Inner Diameter & Height plus Wall, Base, and optional Cover thickness.
- Enter a Waste / Overage % (commonly 5–10%).
- Click Calculate to reveal Net and With Waste volumes in m³, yd³, and ft³.
- Use the Cubic Yards helper (+5% / +10%) and Print / Save Calculations for ordering.
Formulas Used in the Calculator
- Volume = Length × Width × Depth
All dimensions are converted to a single base before multiplication.
- Section Area = Depth × (Top Width + Bottom Width) ÷ 2
- Volume = Length × Section Area
- Outer: (L + 2t_w) × (W + 2t_w) × (H + t_base + t_top)
- Inner: L × W × H
- Net Concrete = Outer − Inner
- Breakdown: Base = Outer Footprint × t_base; Cover = Outer Footprint × t_top; Walls = Net − Base − Cover
- Outer: π × (D_out/2)² × (H + t_base + t_top), where D_out = D_in + 2t_w
- Inner: π × (D_in/2)² × H
- Net Concrete = Outer − Inner
- Breakdown: Base = π × (D_out/2)² × t_base; Cover = π × (D_out/2)² × t_top; Walls = Net − Base − Cover
- With Waste = Net × (1 + Waste%)
- yd³ = m³ × 1.30795
- ft³ = m³ × 35.3147
Frequently Asked Questions
Can I calculate both rectangular and trapezoidal trenches?
Yes. Choose Rectangular to use a single width, or Trapezoidal to enter top and bottom widths; the calculator uses the correct area formula.
How are tank volumes computed?
Both tank modes compute an outer concrete shell minus the inner water volume. We also show a breakdown for base slab, walls, and cover slab.
Which units can I use?
Meters, centimeters, feet, or inches. Pick one unit and enter all dimensions consistently; the tool converts internally.
What waste percentage should I add?
5–10% is common for over-excavation and placement losses. Use higher allowances if site access or formwork is challenging.
How do I get cubic yards for ordering?
After calculating, yardage is shown along with +5% and +10% helpers to round orders to supplier increments.
Can I print or save the results?
Yes. Use the Print / Save function to export an A4-friendly summary with inputs, volumes, breakdown, and yardage.
Does the calculator handle reinforcement or water-tightness checks?
No. It focuses on concrete volume. Reinforcement, crack control, and waterproofing must follow your design and local codes.
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