ConcreteCalc
Calculate concrete

Round and annular volume

Concrete calculator for round post holes

Enter outer diameter, depth and hole count. Optionally subtract a round post diameter to estimate only the annular concrete volume.

Measure diameters and depth

The tool uses π × (outer radius² − inner radius²) × depth × quantity. Leave inner diameter empty for a solid round volume.

Subtract only a round object

The optional inner diameter represents a centered round post or void. It must be smaller than the hole and does not model square posts, irregular excavation or off-centre placement.

Frontend-only calculator

Build your concrete estimate

No account · No saved estimate

Shape and units

Geometry
Measurement system

Changing the measurement system loads reviewed starter values. It never converts or silently reinterprets work in progress.

Round dimensions

Use this shape for a round hole, column or tube with an optional round inner diameter.

Optional; leave empty for a solid round volume
Your explicit allowance; 0% means none

Optional purchase estimate

Enter the volume yielded by one bag from the exact product label. ConcreteCalc never guesses yield from package mass.

Volume estimate only: no structural design, mix selection, thickness advice, reinforcement, site conditions or hidden waste allowance.

Finite SEO catalog

Three useful concrete references

These reviewed pages answer stable volume and package questions. User dimensions, yields, prices and results never create indexable URLs.

Concrete slab volume calculator

Calculate a slab, pad, wall or rectangular footing from its measured dimensions.

Open guide

Concrete bag calculator using label yield

Turn calculated volume into whole bags using the packaged yield you enter.

Open guide

Concrete calculator for round post holes

Calculate round holes or tubes with optional round-post displacement.

Open guide