# How many 50lb bags of concrete per fence post?

Bag yields come off the manufacturer data sheet. An 80 lb bag yields about 0.60 ft³, so a cubic yard (27 ft³) takes roughly 45 bags. A 60 lb bag is about 0.45 ft³ or 60 bags per yard; 50 lb is about 0.375 ft³ or 72 bags; 40 lb is about 0.30 ft³ or 90 bags.

## Short version

## Common mistakes

- **Skipping the cure** — concrete hardens by hydration, and drying it out early costs strength permanently
- **Ignoring exposure class** — freeze-thaw and deicing salt require air entrainment under ACI 318
- **Treating a jurisdiction-specific requirement as universal** — frost depth, permits and code editions are set locally