Concrete Calculator

Calculate concrete needed for slabs, columns, and walls. Get cubic yards, number of bags, and cost estimates. Includes waste factor and common project presets.

Share
Common Project Presets
Cubic Yards
2.47
Cubic Feet
66.67
80lb Bags
112
60lb Bags
149
With 10% Waste Factor
Cubic Yards
2.72
+0.25 extra
80lb Bags
123
+11 extra
60lb Bags
163
+14 extra
Ready-Mix vs Bag Comparison
Ready-Mix Truck
$407
2.72 yd3 x $150/yd3
Best value
Best for 1+ cubic yards
80lb Bags
$728
112 bags x $6.50/bag
0.60 cu ft each
60lb Bags
$820
149 bags x $5.50/bag
0.45 cu ft each
Tip: For projects over 1 cubic yard, ready-mix delivery is usually more economical and provides better consistency. For small projects under 0.5 cubic yards, bags are more practical.
Volume Conversions
Cubic Feet
66.67
Cubic Yards
2.47
Cubic Meters
1.89
Liters
1,888
Weight (approx)
10,000 lbs
Weight (metric)
4,536 kg
Recommended Concrete Thickness
ProjectThicknessPSI Rating
Sidewalk / Path4"3,000
Patio / Floor Slab4"3,500
Driveway (cars)4-6"4,000
Driveway (heavy vehicles)6-8"4,500
Foundation / Footing6-12"4,000+
Retaining Wall6-8"4,000

How to Use Concrete Calculator

  1. 1Select shape: slab, column, or wall
  2. 2Enter dimensions
  3. 3Set waste factor percentage
  4. 4View cubic yards and bags needed

Frequently Asked Questions

How much concrete do I need?

Calculate cubic footage (L×W×depth in feet), then divide by 27 to get cubic yards. A 10×10 ft patio at 4 inches thick needs about 1.24 cubic yards.

How many bags of concrete per cubic yard?

A cubic yard requires approximately 60 bags of 60-lb concrete mix or 45 bags of 80-lb mix. For large projects, ordering ready-mix by the truck is more economical.

How thick should a concrete slab be?

Sidewalks: 4 inches. Patios: 4 inches. Driveways: 4-6 inches. Garage floors: 4-6 inches. Foundation: 8-12 inches.

About Concrete Calculator

Calculate concrete needed for slabs, columns, and walls. Get cubic yards, number of bags, and cost estimates. Includes waste factor and common project presets.

NexTool's Concrete Calculator is completely free to use with no sign-up required. Your data is processed directly in your browser and never sent to our servers, ensuring complete privacy and instant results.

Stay Updated

Get notified about new tools, features, and exclusive deals. No spam, ever.