| Date | Qty | Diameter | Height | Wastage % | Per col. (m³) | Total (m³) | Total (yd³) | Bags 25kg | Bags 40lb | Bags 60lb | Bags 80lb |
|---|
Cylindrical volume: \( V = \pi \times \left(\frac{D}{2}\right)^2 \times H \)
- D = column diameter; H = column height (same units).
- Convert all inputs to meters, compute \(V_{m^3}\), then convert to yd³ and ft³.
- Total volume =
V_per_column × quantity, then apply wastage:V_total × (1 + waste%). - Bag counts =
V_total_m³ ÷ yield_m³_per_bag(rounded up).
- Enter number of columns, diameter, height, and wastage allowance.
- Choose units for diameter and height; the tool converts automatically.
- Review or edit bag-yield presets to match your preferred brand.
- Click Calculate to see per-column and total volumes plus bags.
- Click Add to table to store the scenario for exporting.
- Use Download CSV or Download PDF to share or archive.
Which tube diameters are most common?
Nominal sizes like 8", 10", 12", 16", and 18" are widely available. Always confirm the actual internal diameter printed on the tube.
Should I add a wastage allowance?
Yes. Field conditions, spillage, over-excavation, and uneven bottoms often require extra concrete. A 5–10% allowance is common practice.
Do bag yields differ by brand?
They do. Presets are typical values, but you should adjust them to match the manufacturer’s stated yield for the exact product you plan to use.
Can I enter metric and imperial units together?
Yes. Pick any units per field. The calculator converts to meters internally, then shows results in m³, yd³, and ft³.
How are bags rounded?
Bag counts are rounded up to ensure you buy enough material for the pour. Partial bags are not practical for ordering.
Does this include a belled footing?
No. This model treats a straight cylinder. For belled footings, calculate the bell volume separately and add it to the total.