🧱 Sonotube Calculator

Calculate concrete needed for sonotube columns

Height of the sonotube column

How to Use This Calculator

1

Select Tube Diameter

Choose your sonotube diameter in inches. Common sizes are 8 inches, 12 inches (standard for deck posts), 16 inches, or 24 inches (for large columns). Check your sonotube product specifications.

2

Enter Tube Height

Input the height of your sonotube column in feet. This is the total height of the tube from bottom to top where you'll pour concrete.

3

Specify Number of Tubes

Enter the number of sonotube columns you need. The calculator will multiply the volume per tube by the number of tubes to get total concrete needed.

4

Calculate and Order

Click "Calculate Sonotube" to see concrete needed in cubic yards, cubic feet, and bags. Add 10% extra for waste. Order ready-mix concrete for large projects or bagged concrete for small projects.

Formula

Radius (feet) = Diameter (inches) ÷ 2 ÷ 12

Volume per Tube = π × (Radius)² × Height

Total Volume = Volume per Tube × Number of Tubes

Cubic Yards = Total Volume (cubic feet) ÷ 27

Example 1: Standard Deck Post (12 inch diameter, 4 feet height)

Step 1: Convert diameter: 12 inches ÷ 12 = 1 foot diameter, radius = 0.5 feet

Step 2: Calculate volume: π × 0.5² × 4 = π × 0.25 × 4 = 3.14 cubic feet

Step 3: Convert to yards: 3.14 ÷ 27 = 0.12 cubic yards

Step 4: Calculate bags: 3.14 ÷ 0.6 = 6 bags (80 lb each)

Step 5: Add waste: 0.12 × 1.10 = 0.13 cubic yards (with 10% waste)

Example 2: Large Column (24 inch diameter, 6 feet height)

Step 1: Convert diameter: 24 inches ÷ 12 = 2 foot diameter, radius = 1 foot

Step 2: Calculate volume: π × 1² × 6 = π × 1 × 6 = 18.85 cubic feet

Step 3: Convert to yards: 18.85 ÷ 27 = 0.70 cubic yards

Step 4: For 4 columns: 0.70 × 4 = 2.80 cubic yards

About Sonotube Calculator

The Sonotube Calculator is an essential tool for contractors, builders, carpenters, and DIY enthusiasts who need to accurately determine how much concrete is required for sonotube (cardboard tube) columns, posts, and piers. This calculator eliminates guesswork by providing precise concrete volume calculations based on tube diameter and height, helping you order the right amount of concrete without waste or shortages.

When to Use This Calculator

  • Deck Post Installation: Calculate concrete needed for deck post footings using sonotube columns
  • Foundation Piers: Determine concrete quantities for foundation piers or support columns
  • Column Construction: Estimate concrete needed for structural columns or posts
  • Post Footings: Calculate concrete for post footings for fences, decks, or structures
  • Budget Planning: Calculate material costs by determining exact concrete quantities needed

Why Use Our Calculator?

  • ✅ Accurate Volume: Precise calculations prevent over-ordering or running short
  • ✅ Multiple Tubes: Calculates total concrete for any number of sonotube columns
  • ✅ Multiple Units: Shows results in cubic yards (for delivery), cubic feet, and bags
  • ✅ Bag Calculations: Provides bag counts for 80-pound concrete bags
  • ✅ Cost Planning: Helps budget accurately by determining exact material needs
  • ✅ Time Savings: Instant calculations eliminate manual math and measurements

Common Applications

Deck Post Footings: Homeowners and contractors planning deck installations use this calculator to order the correct quantity of concrete for deck post footings. Standard deck posts use 12-inch diameter sonotube columns at 4-6 feet depth, which this calculator helps determine accurately.

Foundation Piers: Contractors and builders planning foundation piers use this tool to estimate concrete quantities needed. Foundation piers typically use larger diameter sonotube columns (16-24 inches) at deeper depths (6-8 feet).

Structural Columns: Builders and contractors planning structural columns use this calculator to determine concrete quantities needed, ensuring sufficient materials are on-site before starting work.

Tips for Best Results

  • Sonotube Sizes: Common sizes: 8", 12" (deck posts), 16", 24" (large columns)
  • Depth Requirements: Typically 1/3 of post height above ground, or below frost line
  • Add Waste: Always add 10% extra for waste, spillage, and mistakes during pouring
  • Concrete Mix: Use appropriate concrete mix (2,500-3,000 psi) for structural posts
  • Order Ready-Mix: For large projects (10+ tubes), order ready-mix concrete by cubic yards

Frequently Asked Questions

How much concrete do I need for a 12-inch sonotube that is 4 feet tall?

A 12-inch diameter sonotube at 4 feet tall requires approximately 0.12 cubic yards of concrete (3.14 cubic feet), or about 6 bags of 80-pound concrete. Add 10% extra for waste, so plan for about 0.13 cubic yards or 7 bags total.

What size sonotube do I need for deck posts?

Standard deck posts typically use 12-inch diameter sonotube columns. Larger decks or heavier loads may require 14-16 inch diameter. Sonotube depth should be 1/3 of post height above ground, or below frost line in cold climates. Check local building codes for requirements.

How deep should a sonotube be for a deck post?

Sonotube depth should be 1/3 of the post height above ground. For a 6-foot post above ground, use 2-foot deep sonotube. In cold climates, dig below the frost line (typically 30-48 inches deep). Always check local building codes for specific depth requirements.

Do I need to add extra concrete for waste?

Yes! Always add 10% extra for waste, spillage, and mistakes during pouring. If you need 0.12 cubic yards, order about 0.13 cubic yards (with 10% waste) to ensure you have enough concrete.

Can I use bagged concrete for sonotube columns?

Yes! For small projects (1-5 tubes), bagged concrete is convenient. For larger projects (10+ tubes), ready-mix concrete is more economical and efficient. Calculate total volume to decide which is better for your project.

What type of concrete should I use for sonotube columns?

Use standard concrete mix (2,500-3,000 psi) for most sonotube columns. For structural columns or heavy loads, use 3,000+ psi concrete. Ready-mix concrete is convenient for large projects; bagged concrete works well for small projects.