← Home & Construction Calculators
Estimate concrete, premix bags, ready-mix cost, form contact area and vertical reinforcement length for circular, square or rectangular columns.
Column formulas and symbols
V is volume, d is diameter, H is height and Q is quantity. The calculator converts every measurement to feet before calculating.
Worked example
Four round columns, each 16 inches in diameter and 10 feet high, contain about 55.85 ft³ before allowance. With 10% allowance, order about 2.28 yd³.
Visual guide
Measure inside form faces. Calculate capitals, pedestals or enlarged bases as separate shapes.
Planning checklist
- Confirm column shape and clear concrete dimensions.
- Check form plumb, bracing and release agent.
- Verify bar count, ties, lap lengths and concrete cover.
- Coordinate dowels, anchors and embedded items.
- Plan placement lifts, vibration and access.
- Confirm curing and stripping requirements.
The vertical-bar result includes 10% for laps and cutting but does not estimate ties or bar weight.
Frequently asked questions
Is diameter the same as radius?
No. Radius is half the diameter. The calculator accepts diameter.
Does the result include formwork?
It estimates the lateral contact area and an editable formwork cost.
Can I calculate several identical columns?
Yes. Enter the number of columns and all quantities are multiplied automatically.
Does this design reinforcement?
No. Bar count is entered only for a length takeoff. Use approved structural details.
Common mistakes
- Entering radius in the diameter field.
- Forgetting capitals or pedestals.
- Using outside form dimensions.
- Ignoring lap length and waste.