To find the volume of an 80lb bag of concrete cubic feet or in cubic yards, you need to know the density or specific gravity of the concrete. Concrete can vary in density, but a typical density of concrete bag is around 133 lb/ft³ (pounds per cubic foot), or 3,600 lb/ft³ (pounds per cubic yard).

The volume of an 80lb bag of concrete express in terms of cubic feet and in cubic yards. Typically for the estimation purpose, an 80lb bag of concrete yields volume about 0.6 cubic feet or 0.022 cubic yards, or 4.5 gallons, or 17 liters, or 0.0169 m3. This is ready mix to use as concrete contains mix blended of Portland cement, sand, gravel and other approved ingredients.

An 80lb bag of concrete can be used for various projects, such as casting of footing, columns, beams, setting fence posts, creating concrete slabs, sidewalk, driveway, ramp, curbs, walkways or patios, retaining walls and crafting garden structures like stepping stones or planters.

In United States, based on Imperial measurement system, 1 cubic yard is unit of measurement of volume represented by 3 feet long by 3 feet wide by 3 feet depth (3’×3’×3′ = 27 cubic feer), so 1 cubic yard is equal to 27 cubic feet.

The unit weight or density of premix bag of concrete is ratio of unit mass to density. The specific weight of premix bag of concrete is typically about 133 pounds per cubic foot (lb/ft³), or 3,600 pounds per cubic yard (lb/yd³).

An 80 pounds bag of Quikrete’s or Sakrete’s premixed concrete yields volume about 0.60 cubic feet or 0.022 cubic yards, and covers 3.6 square feet area up to standard depth of 2 inches and costs about $4 to $5 per bag.

**How many cubic feet in an 80lb bag of concrete**

To calculate the yields of an 80lb bag of concrete in cubic feet, divide the bag weight by weight of concrete bag per cubic foot, such as the volume of an 80-pound bag of concrete in cubic feet = 80/133 = 0.6 cubic feet.

To calculate the yields of an 80lb bag of concrete in cubic yards, divide the bag weight by weight of concrete bag per cubic yard, such as the volume of an 80-pound bag of concrete in cubic yard = 80/3,600 = 0.022 cubic feet.

Each 80-pound bag of Quikrete or sakrete concrete mix yields approximately 0.6 cubic feet. For a 4′ x 4.5′ x 4″ slab, you will need 6 cubic feet of concrete, or 10 80-pound bags.

If you want to convert cubic feet of concrete in gallons, remember 1 gallon of concrete is equal to 0.13 cubic feet, so 0.6 cubic feet volume of an 80lb bag of concrete is equal to 4.5 gallons (because 0.6/0.13 = 4.5 gallons).

**Conclusions:**Therefore, there would be 0.6 cubic feet, or 0.22 cubic yards in an 80lb bag of concrete. If you measure in other units, the volume of an 80-pound bag of concrete is typically around 4.5 gallons, or 17 liters or 0.0169 m3.