Quick start
- Enter the inside diameter of the round tube or form in inches, not the radius.
- Enter the filled concrete height in feet.
- Enter the number of matching round columns or piers.
- Add waste for form variation, overfill, small spills, and ordering cushion.
Best uses
Start here if one of these sounds like your job. The examples below show which inputs matter most.
- Estimate concrete for round tube forms.
- Compare 12-inch, 16-inch, and 18-inch pier sizes.
- Plan bag counts for small column pours.
- Add waste before pricing ready-mix or bagged concrete.
What this calculator is solving
The Concrete Column Calculator estimates concrete for round columns, piers, and tube forms using cylinder volume.
Match each input label on the calculator to the real measurement, amount, rate, unit, or setting for your job.
The formula in plain language
In plain language: The calculator converts inside diameter from inches to feet, divides by two for radius, uses pi times radius squared times filled height, multiplies by quantity, adds waste, converts to cubic yards, and rounds bag counts up. The examples on the page are there so you can compare your inputs with a worked example before copying the answer.
The math is cylinder volume: pi times radius squared times height. The calculator converts the inside diameter from inches to feet, divides by two for radius, multiplies by filled height and quantity, then adds waste.
How to read the answer
Use cubic yards for ready-mix checks and bag counts for small pours. If the column has a bell, wider footing, square base, or heavy reinforcement, estimate that part separately.
- Cubic feet shows the adjusted volume after waste.
- Cubic yards is the same total divided by 27.
- 60 lb and 80 lb bag counts are rounded up to whole bags.
- For example, three 18 inch columns filled 8 feet high with 10% waste need about 46.65 cubic feet, 1.73 cubic yards, and 78 eighty-pound bags.
Common mistakes to avoid
Most column mistakes come from using outside tube diameter, forgetting waste, or treating a material estimate like a structural design.
- Do not enter outside tube diameter if the inside diameter is smaller.
- Do not forget wider footing bases, bell bottoms, anchor bolts, rebar cages, or form bracing.
- Do not use this as a reinforced-column design calculator.
- Check form size, filled height, frost depth, soil, inspections, and project drawings before buying concrete.
Quick round pier example
Say you have three round piers, each with an 18 inch inside diameter and 8 feet of filled height. The radius is 9 inches, or 0.75 feet.
One pier is about 14.14 cubic feet before waste. Three piers with 10% waste come out near 46.65 cubic feet, which is about 1.73 cubic yards.
Using a common 0.60 cubic foot yield for an 80 lb bag, that rounds up to 78 eighty-pound bags. Always check the bag label because yields can vary.
When a column is not just a cylinder
This calculator is for the straight round part of a column or pier. It does not add a bell footing, flared base, square pad, pier cap, anchor hardware, or rebar cage.
If your plan has one of those pieces, calculate it separately or use the takeoff from the designer, engineer, permit drawing, or contractor.
Why the limit note matters
Concrete volume is not the same thing as column design. Loads, soil, frost depth, reinforcement, inspection rules, and local code decide whether a pier is safe.
Use this page to buy roughly the right amount of concrete. Use approved plans or a qualified professional to choose the actual pier size and reinforcement.
Research and references
These references help check the measurements, units, limits, or safety notes used in this guide.
Worked examples for Concrete Column Calculator
46.65 ft3, about 1.73 yd3, 78 eighty-pound bags
10.18 ft3, about 0.38 yd3, 17 eighty-pound bags
14.14 ft3, about 0.52 yd3, 24 eighty-pound bags
7.33 ft3, about 0.27 yd3
FAQ in plain language
When should I use the Concrete Column Calculator?
Use it when your task matches one of these common needs: Estimate concrete for round tube forms. Compare 12-inch, 16-inch, and 18-inch pier sizes. It works best when you already know the measurements, amounts, units, or options the page asks for.
What is the Concrete Column Calculator doing with my inputs?
In plain language: The calculator converts inside diameter from inches to feet, divides by two for radius, uses pi times radius squared times filled height, multiplies by quantity, adds waste, converts to cubic yards, and rounds bag counts up. The examples on the page are there so you can compare your inputs with a worked example before copying the answer.
What do the main Concrete Column Calculator inputs mean?
Inside diameter: the clear width across the inside of the round tube or form, measured in inches. Filled height: the height of concrete inside the form, measured in feet. Quantity: how many matching round columns or piers are included. Waste percent: extra concrete for form variation, spillage, overfill, and ordering cushion.
How should I read the Concrete Column Calculator answer?
Read the headline estimate first, then check the material, waste, coverage, and unit lines. For project tools, the supporting lines are often the difference between a rough idea and a list you can actually shop from.
What should I double-check before trusting the answer?
This is material volume math only. Footing bells, flared bases, reinforcement, anchors, structural loads, form bracing, vibration, soil, frost depth, inspections, and local code can change the real pour. Also check the unit, scale, mode, and result limit because small input changes can change the answer.
What does diameter mean for a concrete column?
Diameter is the full width across the round form. The calculator divides it by two to get radius, then uses the cylinder formula. Do not enter radius in the diameter box.
Does this include a wider footing or bell at the bottom?
No. It estimates the straight round column only. If your pier has a widened base, calculate that extra concrete separately or ask the designer for the takeoff.
Related tools
- Concrete Footing CalculatorEstimate concrete volume and bag counts for straight rectangular footings.
- Post Hole Concrete CalculatorEstimate concrete bag counts for fence, deck, and mailbox post holes.
- Concrete CalculatorEstimate slab volume, cubic yards, cubic meters, and common 40, 60, and 80 lb bag counts.
- Cubic Yard CalculatorConvert length, width, depth, and waste into cubic feet and cubic yards.
Keep exploring
If this guide is close but not exact, these links keep you near the same kind of problem.
- Home & ProjectsBrowse the full category for related tools that help with the same job.
- All free toolsSearch the complete Access Free Tools library by task, category, or tool name.
- All calculator and utility guidesFind more plain-language examples, formulas, mistakes, and result explanations.
- Free calculator resourcesStart here when you are not sure which calculator page fits.
Privacy and copying results
Recent answers stay visible only while you work in the current browser tab. They are not sent to a server.
Use Copy answer when you want to save the inputs and result in notes, homework, a message, or a project list. Check the units, labels, and limits before copying.