Footing planning

Post Hole Concrete Calculator

Estimate concrete for round post holes used in fences, decks, pergolas, and similar projects. Enter hole size, depth, post size, quantity, bag size, and waste allowance.

Project inputs

Start with your actual measurements.

Results update in your browser. Measurements and prices are not sent to a server.

How the estimate works

Use the number as a planning starting point.

The calculator subtracts the square post volume from a cylindrical hole volume, then converts the result into cubic feet, cubic yards, and a conservative bag estimate.

Measure first

Measure finished dimensions, actual stock, openings, and site constraints before ordering material.

Check the result

Hole diameter, frost depth, soil condition, drainage, and approved footing details vary by location. Confirm the required footing design with local requirements before building.

Plan the next step

Use the related calculators below to turn a first estimate into a material list, layout, or a more detailed project plan.

FAQ

Common Post Hole Concrete Calculator questions

How many concrete bags fit in a post hole?

It depends on the net hole volume after the post displaces material. The calculator shows an estimate for the bag weight you choose.

Should I add waste to concrete?

Yes. A small allowance helps account for irregular holes, spillage, and mixing loss.

Related tools

Keep the project moving.

Fence Calculator

Free fence calculator for posts, pickets, rails, concrete, waste allowance, and material cost. Plan a wood fence before buying materials.

Open Fence Calculator

Deck Cost & Material Calculator

Free deck cost and material calculator. Estimate decking boards, joists, fasteners, waste allowance, and a starting material budget.

Open Deck Cost & Material Calculator

Picket Spacing Calculator

Free picket spacing calculator. Find fence picket quantity, equal gaps, and layout marks from fence length, picket width, and target gap.

Open Picket Spacing Calculator

Roof Pitch Calculator

Free roof pitch calculator. Convert rise and run into roof pitch, angle, slope percentage, pitch multiplier, and an approximate common-rafter length.

Open Roof Pitch Calculator

Planning disclaimer: WoodCutTool results are estimates. Verify measurements, product instructions, material condition, local requirements, and safety practices before buying, cutting, or building.