Post Size Calculator Pro (USA)
Accurate Concrete & Post Layout Estimator for Fence & Deck Projects
Project Dimensions
Concrete Estimation Results
Fence/Deck Layout Estimator
Calculate how many posts you need for your project line.
Material Requirements
Expert Guide: Setting Posts in the USA
Using a Post Size Calculator Pro (USA) ensures that you purchase the exact amount of concrete required for your fencing or decking project, saving money and time.
How Deep Should a Post Hole Be?
A general rule of thumb in the USA construction industry is the “1/3 Rule”. The depth of the hole should be at least 1/3 the height of the post above ground. For a standard 6-foot fence, aim for a hole depth of 24 to 36 inches to account for frost lines in northern states.
Calculating Concrete Volume
Our tool calculates the volume of the cylinder (hole) and subtracts the volume of the square post.
Formula Used:
Concrete Volume = (Hole Area × Depth) - (Post Area × Depth)
Why Use Bagged Concrete?
For small to medium projects (up to 20 posts), 60lb or 80lb bags of Quikrete or similar brands are ideal. They are mixed with water directly in the hole. Always round up your calculations to ensure you don’t run short mid-project.
