Type the size in feet and inches.
⚙️Calculation Parameters
📊Calculated Output
How Imperial Sonotube Calculator Works?
To size a Sonotube in imperial units, the Imperial Sonotube Calculator takes diameter in inches (in) and depth in feet (ft) and inches, then returns cubic feet (ft³), cubic yards (yd³) and US bag counts. The process takes 4 steps.
Enter diameter in inches
Type the tube size from the label: 6 in, 8 in, 10 in, 12 in, 14 in, 16 in, 18 in or 24 in.
Enter depth in feet and inches
Type the depth the way a tape measure reads it, such as 3 ft 6 in. The calculator converts the reading to decimal feet.
Read ft³ and yd³
The calculator shows ft³ for bag math and yd³ for truck orders.
Read pound-bag counts
The tool divides the ft³ total by 0.60 ft³ for 80 lb bags and 0.45 ft³ for 60 lb bags and rounds up.
Imperial Sonotube Calculator Formula
The Imperial Sonotube Calculator converts inches and feet into one unit before applying the cylinder formula.
Depth to decimal feet
H (ft) = feet + inches ÷ 123 ft 6 in = 3 + 6 ÷ 12 = 3.5 ft.
Volume in ft³
V = π × (D ÷ 24)² × HD in inches, H in decimal feet.
Cubic yards
V (yd³) = V (ft³) ÷ 2727 ft³ = 1 yd³.
Worked example: 10 in tube, 3 ft 6 in deep
- H = 3 + 6 ÷ 12 = 3.5 ft
- V = 3.1416 × (10 ÷ 24)² × 3.5 = 1.909 ft³
- 1.909 ft³ = 0.0707 yd³, or 4 bags of 80 lb (36 kg) mix
Imperial Sonotube Calculator Conversion Table
The imperial conversion table lists 4 popular diameters at 3 ft (0.91 m) and 4 ft (1.22 m) depths with pound-bag counts.
| Diameter | Depth | ft³ | yd³ | 80 lb bags | 60 lb bags |
|---|---|---|---|---|---|
| 8 in | 3 ft 0 in | 1.05 | 0.039 | 2 | 3 |
| 8 in | 4 ft 0 in | 1.40 | 0.052 | 3 | 4 |
| 10 in | 3 ft 0 in | 1.64 | 0.061 | 3 | 4 |
| 10 in | 4 ft 0 in | 2.18 | 0.081 | 4 | 5 |
| 12 in | 3 ft 0 in | 2.36 | 0.087 | 4 | 6 |
| 12 in | 4 ft 0 in | 3.14 | 0.116 | 6 | 7 |
| 16 in | 3 ft 0 in | 4.19 | 0.155 | 7 | 10 |
| 16 in | 4 ft 0 in | 5.59 | 0.207 | 10 | 13 |
Bag counts are rounded up per tube with no waste margin.
What is Imperial Sonotube Calculator?
An Imperial Sonotube Calculator is a concrete form calculator built for inches, feet and pound bags, the units used on United States (US) job sites, lumberyard labels and building codes.
US deck codes, such as the American Wood Council (AWC) DCA 6 deck guide, list pier sizes in inches and frost depths in inches or feet. The calculator reads those values without conversion and outputs the 80 lb, 60 lb and 50 lb bag counts sold at US stores.
A 12 in × 4 ft pier holds 3.14 ft³, which equals 0.116 yd³ or 6 bags of 80 lb concrete.
What are the uses of Imperial Sonotube Calculator?
There are 4 main uses of the Imperial Sonotube Calculator.
Code-based deck footings
Builders size piers from inch and foot values in a US permit set.
Store bag counts
Shoppers get counts in the 80 lb, 60 lb and 50 lb sizes sold in the US.
Tape-measure input
Crews enter readings like 3 ft 9 in without converting to decimals.
Truck orders
Contractors read the yd³ value US ready-mix plants use.