Free Concrete Bag Calculator AppSlabs, Columns & Post Holes40, 50, 60, 80 lb Bags & 25kg

Concrete Bag Calculator

Calculate how many pre-mixed concrete bags (40, 50, 60, 80 lb or 25kg) and total cubic yards you need for slabs, footings, columns, and post holes.

1. Project Shape & Units
Standard 4" for sidewalks/patios, 5-6" for driveways
Recommended Waste Allowance:+10%
Total Volume Required

1.36 Cubic Yards

(36.7 cu ft / 1.04 cubic meters)

Most Popular Choice
62 Bags
(80 lb pre-mix bags)
80 lb Bags
62
0.60 cu ft yield
60 lb Bags
82
0.45 cu ft yield
50 lb Fast-Set
98
0.375 cu ft yield
25 kg Metric
87
0.012 m³ yield
DIY Friendly Bag Pour:At 1.36 cubic yards (62 bags), this project can be easily mixed on-site using a standard wheelbarrow or rented electric drum mixer.
3D Volume Projection DiagramSLAB
10 x 10 (4" thick)

Frequently Asked Questions (Concrete Bag FAQ)

How many 80 lb bags of concrete make a cubic yard?

It takes 45 bags of 80 lb concrete to make one cubic yard (27 cubic feet). One 80 lb bag yields approximately 0.60 cubic feet of mixed concrete.

How many 60 lb bags of concrete make a cubic yard?

It takes 60 bags of 60 lb concrete to make one cubic yard. One 60 lb bag yields approximately 0.45 cubic feet.

How many bags of concrete do I need for a 10x10 slab?

A 10x10 foot slab poured at 4 inches thick requires 1.23 cubic yards (33.3 cubic feet) of concrete. With 10% waste, you will need approximately 61 bags of 80 lb concrete or 82 bags of 60 lb concrete.

When should I order a concrete truck instead of bags?

If your project requires more than 1.5 to 2 cubic yards of concrete (more than 60-90 bags of 80 lb concrete), ordering a ready-mix concrete delivery truck is usually more cost-effective and avoids hours of manual mixing labor.