Overview
What is the Concrete Column Calculator?
This column calculator uses the rectangular-prism engine: plan length × plan width × height. It is for square and rectangular piers, not round columns. Circular columns remain available on the main concrete calculator. Structural ties, cover, and load design are outside the takeoff.
Rectangular columns are plan size times pour height. Enter length, width, and height for piers, pedestals, and square columns, then set quantity for a row of identical members. The page returns volume, bags, and weight so you can stage mix per column instead of guessing from leftover slab concrete.
Workflow
How does it work?
Each plan dimension and the pour height convert to metres, then multiply. Quantity repeats identical columns. Waste covers over-pour at the top of the form. Bags and weight use the same yields and density as other Calnovix concrete pages.
Set Imperial or Metric so plan size and height match the drawing units.
Choose Column so the form multiplies length × width × height instead of a slab thickness.
Enter the formed plan size and the pour height to the top of concrete.
Set quantity to the number of identical piers in the row.
Add a modest waste percentage for over-pour and spillage at each form.
Read total cubic yards, then decide whether bags or a short ready-mix load fits the site.
Math
Formula
Volume = length × width × height × quantity × (1 + waste%)
A rectangular column is a vertical box. Plan length and width are the formed section; height is the pour. Quantity multiplies identical members. Waste scales the total. Round columns use πr² × height on the main concrete page, not this rectangular formula.
Inputs
Step-by-step variables
L
Plan length
One side of the rectangular section as formed.
W
Plan width
The other side of the section. Square piers use equal L and W.
H
Height
Vertical pour height of the column or pier.
Practice
Step-by-step examples
Four 12 × 12 in piers, 4 ft high
Each pier is 1 ft × 1 ft × 4 ft = 4 ft³. Four piers are 16 ft³, or 0.59 yd³ raw, with 10% waste.
About 0.65 yd³ after waste (≈ 0.50 m³). Bags are often practical at this size; check the 80 lb count on the result card.
One 18 × 18 in pedestal, 3 ft high
Plan size 1.5 ft × 1.5 ft, height 3 ft. Volume is 6.75 ft³, or 0.25 yd³ before waste.
About 0.28 yd³ with 10% waste. A small bagged mix order usually covers a single pedestal.
Where it helps
Use cases
- Deck and porch piers poured in cardboard or timber forms
- Square columns in a carport or canopy line
- Pedestals under equipment pads
Avoid these
Common mistakes
- Using the round-column formula on a square pier, which under- or over-orders.
- Entering plan size in inches as if they were feet (12 instead of 1).
- Forgetting quantity when several identical piers share one mix order.
Buying & planning
Tips
- Measure the inside of the form, not the outside of the tube.
- Keep post-hole volume on its own page when the pier sits in a dug hole rather than a formed column.
- Brace forms before the pour; volume math cannot save a blown form.
Need the bigger picture? Read our calculator disclaimer and accuracy policy.