Add the parts of the tube below and above ground.
⚙️Calculation Parameters
📊Calculated Output
How Sonotube Embedded Length Calculator Works?
To find total form length, the Sonotube Embedded Length Calculator adds the below-grade depth and the above-grade reveal. The process takes 4 steps.
Enter the frost depth
Type the local frost depth from the building department, in inches (in) or centimeters (cm).
Add the code margin
Enter the extra depth below frost. Many codes require the pier bottom at least 6 in (15 cm) below the frost line.
Enter the reveal
Type how far the tube sticks out above finished grade, usually 2 in to 12 in (5 cm to 30 cm).
Read the total length
The calculator adds all 3 values and shows the cut length, the form waste and the concrete volume.
Sonotube Embedded Length Calculator Formula
The Sonotube Embedded Length Calculator adds 3 length segments and applies the cylinder formula to the total.
Embedded depth
E = frost depth + marginMargin is commonly 6 in; follow local code.
Total form length
L = E + revealReveal keeps wood posts off wet soil.
Fill volume
V = π × (D ÷ 24)² × (L ÷ 12)D in inches gives cubic feet (ft³).
Worked example: 42 in frost depth, 6 in margin, 8 in reveal, 10 in tube
- E = 42 + 6 = 48 in
- L = 48 + 8 = 56 in (4.67 ft, 142 cm)
- V = 3.1416 × (10 ÷ 24)² × 4.67 = 2.545 ft³
Sonotube Embedded Length Calculator Conversion Table
The embedded length conversion table lists total form lengths for 6 frost depths, using a 6 in margin and a typical reveal, with the fill of a 10 in tube.
| Frost depth | Embedded depth | Reveal | Total length | 10 in tube ft³ |
|---|---|---|---|---|
| 12 in (30 cm) | 18 in | 6 in | 24 in (2.00 ft) | 1.09 |
| 24 in (61 cm) | 30 in | 6 in | 36 in (3.00 ft) | 1.64 |
| 36 in (91 cm) | 42 in | 8 in | 50 in (4.17 ft) | 2.27 |
| 42 in (107 cm) | 48 in | 8 in | 56 in (4.67 ft) | 2.55 |
| 48 in (122 cm) | 54 in | 12 in | 66 in (5.50 ft) | 3.00 |
| 60 in (152 cm) | 66 in | 12 in | 78 in (6.50 ft) | 3.55 |
Frost depths come from local code tables. Confirm the value with the building department.
What is Sonotube Embedded Length Calculator?
A Sonotube Embedded Length Calculator is a form-length tool that adds the buried depth of a tube to the exposed reveal above grade and returns the total length to cut.
Concrete volume depends on total tube length, not just hole depth. A pier dug 48 in deep with an 8 in reveal holds 17% more concrete than the hole depth alone suggests. The calculator includes both parts and reports the cut length.
The tool helps when the frost depth and the reveal come from 2 different sources: the building code and the deck or post design.
What are the uses of Sonotube Embedded Length Calculator?
There are 4 main uses of the Sonotube Embedded Length Calculator.
Tube cut lists
Crews cut each form to the exact length before setting it.
Frost compliance
Builders confirm the pier base sits below code depth.
Reveal planning
Designers set the top of concrete above grade for post bases.
Volume correction
Estimators add the above-grade part that hole-depth math leaves out.
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