Materials

Sonotube Calculator

Calculate concrete bags for round tube forms (Sonotubes). Enter diameter, depth, and number of tubes.

Total Cubic Yards

Frost Line Depth by Region (approx.)

RegionFrost DepthExample States
South / Gulf Coast0–6"FL, TX, LA, GA
Mid-Atlantic / Southeast12–20"VA, NC, TN, AR
Midwest / Mid-South24–36"OH, IN, MO, KS
Upper Midwest / Northeast36–48"PA, NY, MI, WI
Northern / Mountain48–60"MN, ND, MT, ID
Extreme North / Alaska60"+"AK, upper MN

Always verify frost line depth with local building codes. Footings must extend below frost line to prevent heave.

Sonotube Concrete Forms

Sonotubes (round cardboard concrete forms) are used for deck footings, fence posts, pergolas, and columns. The footings must extend below the local frost line to prevent frost heave from lifting the structure. Always consult your local building department for required depth and diameter.

A 60lb bag of Quikrete yields 0.45 cubic feet. An 80lb bag yields 0.60 cubic feet. For most residential deck posts, 10-12" diameter tubes are standard. For larger structures, 16" or wider may be required.

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