How Many Sixty Pound Concrete Bags Per Yard

Figuring out the number of concrete bags needed for a project can be tricky. With variables like concrete density, measurement conversions, and waste factors, it's easy to end up with the wrong estimate.

You'll learn concrete volume per bag, standard yardage coverage rates, and how to adjust your concrete bag count for real-world waste and spillage.

Determining Cubic Yardage for Concrete Projects

The first step in finding 60-pound concrete bag quantities is determining your total cubic yardage need. Cubic yards indicate the concrete's volume - not the surface area it will cover.

Some typical cubic yardages:

• 4-inch thick slab = 0.33 cubic yards per 10 ft x 10 ft section
• 6-inch thick slab = 0.5 cubic yards per 10 ft x 10 ft section
• Footings often require 0.5 to 1 cubic yard

Or use an online concrete calculator by inputting the length, width and thickness of your project. It will calculate the cubic yards required.

Calculating Irregular Areas and Volumes

For irregularly shaped areas like curved walkways or odd-shaped patios, divide the shape into smaller rectangles and triangles to calculate the area. Then use the area and thickness to find cubic yards needed.

Software apps like SmartDraw offer advanced area and volume calculators for complex shapes. Or have ready mix suppliers calculate your yardage need.

How Many 60-Pound Bags of Concrete Mix Are Needed Per Yard

Understanding Bagged vs Bulk Concrete

Bagged concrete mix offers convenience for small-to-medium jobs. It is sold at home improvement stores in 60 or 80-pound bags containing dry premixed concrete. Just add water on site per the manufacturer's directions.

For large pours, bulk/ready mixed concrete is delivered by a truck. It doesn't require on-site mixing or precise measurements by the user.

Concrete Bag Weights and Yields

One 60-pound (27kg) bag of concrete yields about 0.45 cubic feet. An 80-pound bag (36kg) yields approximately 0.60 cubic feet.

The yield refers to the concrete's total volume when mixed. Other typical bag sizes and respective volumes:

• 40 lb = 0.37 cu ft
• 60 lb = 0.45 cu ft
• 80 lb = 0.6 cu ft

Converting Between Cubic Yards, Cubic Feet and Bags

Remember these conversions when estimating:

• 1 cubic yard = 27 cubic feet
• 60 lbs bag concrete = 0.45 cubic feet
• So 1 yard = 60 bags (because 27 cu ft / 0.45 cu ft per bag = 60)

Coverage Rates of 60-Pound Bags

While cubic yards indicate volume, most concrete projects use dimensions of area and thickness. This requires converting between volume and area units.

At a 4-inch slab thickness, one 60-lb bag covers about 2.7 square feet. For other thicknesses:

• 2 inches thick covers 5.4 sq ft per bag
• 4 inches covers 2.7 sq ft per bag
• 6 inches covers 1.8 sq ft per bag

Adjusting Yield for Concrete Strength

Higher strength concrete contains less water, so the yield per bag decreases. Each bag covers 5% to 10% less area for concrete strength:

• 3000 PSI: Standard 5.4 sq ft yield per 2-inch slab
• 4000 PSI: 5% less yield per bag
• 5000 PSI: 10% less yield per bag

Calculating Number of 60-Pound Bags for a Cubic Yard

Concrete Volume Calculations

One cubic yard equals 27 cubic feet (3 ft x 3ft x 3ft).

With 60-pound bags yielding 0.45 cubic feet each, one cubic yard requires:

27 cu ft / 0.45 cu ft per bag = 60 bags

Sixty-Pound Bag Concrete Volume

Another way to calculate bags per yard is by determining the concrete volume within 60-pound bags:

• 1 bag yields 0.45 cu ft
• So 60 bags will yield 60 x 0.45 = 27 cu ft

27 cubic feet equals 1 cubic yard. So 60 lbs bags provide 1 yard.

Determining Total 60-Pound Bags Needed

If your project requires 1.5 cubic yards, multiply the yardage by 60 bags per yard:

1.5 yards x 60 bags/yard = 90 bags

In metric units, 1 cubic meter (m3) also needs 60 x 27kg bags. Because 1 cubic meter = 35.3 cu ft 36 sixty-pound bags 1 cubic yard

Estimating Concrete Bag Requirements for Common Project Dimensions

Standard Concrete Slab, Footing and Sidewalk Dimensions

Here are 60-pound bag estimates for typical project sizes:

• 4 inch slab, 10 ft x 10 ft = 33 bags
• 4 inch slab, 20 ft x 20 ft = 132 bags (1 yard = 81 sq ft at 4 inches thick)
• 6 inch slab, 10 ft x 10 ft = 50 bags
• 12-inch square footings, 2 ft deep = 4 bags
• 4 inch thick sidewalk, 3 ft x 100 ft - 66 bags

Sixty-Pound Bag Estimates for Driveways, Patios, Retaining Walls

Estimates for other common projects:

• 6 inch thick, 10 ft x 12 ft driveway slab - 48 bags
• Paver patio base, 4 in thick, 12 ft x 12 ft - 36 bags
• 8 inch thick retaining wall footer, 60 ft long x 18 inches deep = approx. 110 bags

Use an online concrete calculator for custom dimensions by inputting thickness, length and width.

Adjusting Concrete Yield for Waste and Other Factors

Concrete Yield Loss from Waste and Spills

The above bag number estimates assume full yield without waste. But concrete work inevitably involves unused leftovers, spills, equipment washout, etc. This causes yield loss.

A typical waste factor is between 3% to 20%. Consider your project complexity and concrete handling experience when estimating waste:

• Simple slab or patio, experienced - 3% waste
• Complex forms, footings, amateur - 10% to 15% waste
• Major structural project - add 20% extra bags