🕳️ Post Hole Concrete Calculator for Concrete & Masonry
Estimate concrete for cylindrical post holes.
This free tool helps you turn project measurements into a practical planning estimate. Enter values in Vaelden’s interactive calculator, review the result, and confirm important assumptions against supplier data, measurements, codes or qualified advice before committing materials or money.
Open the Post Hole Concrete calculator →
How to calculate post hole concrete
Method: Concrete = number of holes × depth × π × (hole radius² − post radius²) × contingency
- Measure actual hole diameter and depth.
- Subtract the post displacement where appropriate.
- Multiply by post count and add allowance for irregular excavation.
Worked example
Using these planning inputs:
- Hole diameter: 0.3
- Hole depth: 0.6
- Post diameter: 0.1
- Hole count: 8
- Waste: 10 %
Concrete required: 331.75 L
Reality check: Hole size, embedment, drainage and concrete use depend on wind, soil, post system, loads and local rules.
Before you calculate
Use consistent units and the best measured inputs available. Real materials, equipment, site conditions and tolerances can change the result. Vaelden shows planning estimates; regulated, structural, electrical, plumbing, pressure and other safety-critical work still requires appropriate local compliance and professional advice.