Calculators

Post hole concrete calculator

Post hole concrete calculator: hole diameter, concrete depth, square post width, bag yield, waste allowance.

One layout. Every calculation.

Layout

Each segment starts at the previous endpoint. Gate start and width are distances between post centers; enter zero width for no gate. 0° points right and 90° points up. A closed loop must end at its starting point. The start coordinates apply only when New start is selected.

Budget

No automatic price assumptions. Enter current quotes in one currency.

Results

Connected corner or gate posts are counted once. Gate frame boards and hardware are separate. This is a materials estimate, not a structural design.

Saved projects stay on this device. Nothing is uploaded. Project is not saved until you press Save. Print settings: choose Save as PDF in your browser.

Inputs and assumptions

  • Hole diameter
  • Concrete depth
  • Square post width
  • Bag yield
  • Waste allowance

Each segment starts at the previous endpoint. Gate start and width are distances between post centers; enter zero width for no gate. 0° points right and 90° points up. A closed loop must end at its starting point. The start coordinates apply only when New start is selected.

Formula

V = N × (πD²/4 - p²) × H; B = ceil(V × 1000 × (1 + w/100) / Y)

Count bays before posts

For one uninterrupted straight run, bays = round up(run length ÷ maximum spacing). Posts = bays + 1. This rule applies to that run only. A gate breaks it into two fenced portions with separate gate posts. A shared corner belongs to both runs but is ordered once.

A 12 m run at a 2.4 m maximum spacing has five bays and six posts. Two perpendicular 6 m runs each require three bays. Counting their shared corner once gives seven posts. A closed four-sided loop has no two free ends: add the bays, then count unique junctions.

Our planner divides every fenced interval separately and merges matching endpoint coordinates. Gate posts take priority over corner and line labels. Specify reinforcement and footing requirements separately for gate posts. A post count is not a decision about structural suitability or allowable spacing.

This is a materials estimate, not a structural design. Gate frame boards and hardware are separate. Follow the product label. Yield and coverage are editable.

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