Post Hole Calculator

How many bags of concrete to set fence or deck posts.

60-LB BAGS NEEDED
bags
to set posts

Usage Tip

Dig holes 1/3 the post length deep, flare the bottom, and crown the concrete above grade to shed water.

THE MATH
Concrete = π × r² × depth × 0.7
Where: 0.7 leaves room for the post  •  ÷1728 = cu ft
• 60-lb bag = 0.45 ft³
• Dig holes 1/3 the post length deep
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