Concrete Tube / Pier Calculator — Cylindrical Volume
Enter the tube diameter, depth and number of tubes to get the total concrete volume in cubic metres and cubic yards, with pre-mix bag counts.
Units
cm
m
0.111 yd³ • 3 ft³
0.085 m³
per tube- 1
Radius
0.3 m ÷ 2 = 0.15 - 2
Cross-section area
π × 0.15² = 0.07069Circle area = π × r² - 3
Volume
0.07069 m² × 1.2 m = 0.085
How does this calculator work?
Concrete tube volume = π × (diameter/2)² × depth × number of tubes. A 12 in diameter pier 4 ft deep holds about 0.10 yd³ (0.076 m³) — roughly 5 × 80 lb bags. Multiply by tube count for the total; add 5–10% for waste.
Formula
How this is calculated
A cylindrical tube form (often called a Sonotube) is used to create concrete piers, deck footings and columns. Its cross-section is a circle with area = π × r² where r = diameter / 2. Multiplying the cross-sectional area by the depth gives the volume of one tube. The calculator then multiplies by the number of tubes to get the total volume.
All inputs are converted to metres before computing so that the output is in cubic metres. The cubic-yard and cubic-foot equivalents are derived from the exact conversion 1 yd³ = 0.7646 m³ (1 yd³ = 27 ft³). Bag counts divide the total volume in cubic yards by published manufacturer yields — approximately 0.022 yd³ per 80 lb bag and 0.017 yd³ per 60 lb bag — and round up.
The formula gives the volume of solid concrete for each tube. In practice, add 5–10% extra to account for mixing waste and slightly uneven holes. If the footing contains rebar, the displaced concrete is negligible for typical residential sizes and can be ignored.
Frequently asked questions
A common rule of thumb for residential deck posts is three times the post diameter. For a 4 in (100 mm) post, use at least a 12 in (300 mm) diameter tube; for a 6 in post, use 18 in. Always follow local building codes for frost depth and load requirements.
Piers must extend below the frost line in your area to prevent frost heaving. The frost line ranges from near zero in warm climates to 1.5–2 m (5–6 ft) in northern regions. Check your local building authority for the required depth.
Yes — cylindrical piers are typically small enough that bags are cost-effective and practical. A 12 in × 4 ft pier holds roughly 0.076 m³ (0.10 yd³), needing about 5 × 80 lb bags. For many small piers, dry-pour bag concrete (pour dry mix in, add water to hole) works well for non-critical footings.
Also known as
TG we-Calculate Editorial Team. (2026). Concrete Tube / Pier Calculator — Cylindrical Volume [Online calculator]. TG we-Calculate. https://we-calculate.com/calculator/concrete-tube-calculator
TG we-Calculate Editorial Team. "Concrete Tube / Pier Calculator — Cylindrical Volume." TG we-Calculate. 2026. https://we-calculate.com/calculator/concrete-tube-calculator.
TG we-Calculate Editorial Team, "Concrete Tube / Pier Calculator — Cylindrical Volume," TG we-Calculate, 2026. [Online]. Available: https://we-calculate.com/calculator/concrete-tube-calculator
@misc{wecalculate_concrete_tube_calculator, title = {Concrete Tube / Pier Calculator — Cylindrical Volume}, author = {{TG we-Calculate Editorial Team}}, howpublished = {\url{https://we-calculate.com/calculator/concrete-tube-calculator}}, year = {2026}, note = {TG we-Calculate} }
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