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Concrete Column Calculator

Calculate concrete volume for round columns and piers. Results update instantly as you change the inputs.

Start estimate Read FAQs
Output
yards / bags / cost
Mode
planning estimate
Concrete Column Calculator estimating scene A construction estimating worksheet with concrete forms, bag count notes, a tape measure, and supplier order math. ORDER 0.42 yd3 80 lb live order math waste + rounding
live order math 0.42 yd3

Enter non-negative dimensions for each round column or post hole.

Concrete Column CalculatorEnter dimensionsDiameter, depth or height, and quantity are required before the estimate appears.
Example12 in diameter x 4 ft deep = 0.12 yd³

Use the inside form diameter and include below-grade depth for piers.

Last reviewed: May 12, 2026 by the BuilderCalc editorial team.

Column planning

Concrete Column Calculator planning notes

Round columns and piers are small in plan view but can add up quickly when you multiply by quantity. Measure the inside diameter of the form tube, not the outside label.

Use inside form diameter

A form tube label may not match the exact inside diameter. When precision matters, measure the actual inside opening and depth before calculating.

Group matching piers

Use the quantity field for identical piers. For mixed diameters or depths, calculate each group separately and add the totals.

How to use it

Keep the estimate tied to field measurements

01

Measure inside diameter

Use the inside diameter of the form tube, not the outside label or nominal size.

02

Measure depth or height

Include below-grade depth for piers and the full pour height for above-grade columns.

03

Enter quantity

Use quantity for identical columns. Calculate mixed sizes separately and add the totals.

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Need bag counts instead? Convert slab dimensions into 40 lb, 60 lb, and 80 lb concrete bag counts. Convert to cubic yards Calculate cubic yards of concrete from project dimensions. Work in cubic feet Calculate concrete cubic feet, cubic yards, and cubic meters.

FAQ

Concrete estimating questions

How much concrete do I need for a Sonotube?

A 12 inch diameter by 4 ft deep form tube needs about 0.12 cubic yards, or about six 80 lb bags before waste. Use the calculator for other diameters and depths.

What size Sonotube should I use for a deck post?

Many residential deck posts use 10 inch or 12 inch form tubes. Larger structures, poor soil, or higher loads may require 16 inch or larger piers.

How deep should a footing column be?

In frost-prone climates, pier bottoms usually need to extend below local frost depth, often 36-48 inches. Check your local frost depth and building department guidance.

Do I need rebar in a concrete pier?

Many residential piers use two to four vertical #4 bars with horizontal ties, but reinforcement requirements depend on load, soil, and local code.

How do I calculate multiple columns?

Enter the diameter, depth, and quantity for identical columns. For mixed sizes, calculate each size separately and add the cubic-yard totals.