Free Online Concrete Calculator - Calculate Volume, Weight, Cost and Bags

Choose Concrete Structure Type

Calculator main body

Slabs, Footings, Walls Calculation

Slabs, Footings, Walls

Length (L)

Width (W)

Height (H)

Quantity

Rectangular Slab Diagram with Dimensions

Columns, Circular Slabs Calculation

Columns, Circular Slabs

Diameter (D)

Height (H)

Quantity

Footing Calculation

Footing

Length (L)

Width (W)

Thickness (T)

Quantity

Round Footing Calculation

Round Footing

Radius (R)

Depth (D)

Quantity

Columns, Circular Slabs Calculation

Columns, Circular Slabs

Width (W)

Depth (D)

Height (H)

Quantity

Tubes, Post Holes Calculation

Tubes, Post Holes

Outer Diameter (OD)

Inner Diameter (ID)

Height (H)

Quantity

Curb And Gutter Calculation

Curb And Gutter

Length (L)

Curb Depth (CD)

Curb Height (CH)

Gutter Width (GW)

Flag Thickness (FT)

Quantity

Post Hole Calculation

Post Holes

Radius (R)

Depth (D)

Quantity

Stairs Calculation

Stairs

Platform Depth (PD)

Run (R)

Rise (R)

Width (W)

Stairs Count (SC)

Quantity

Ramps Calculation

Ramps

Height (H)

Width (W)

Length (L)

Quantity

Calculation Results

Advanced Settings

Density: 2140 Unit Price: $0.00

Density:

Unit Price:

Volume:

0.00 cubic meters 0.00 cubic feet 0.00 cubic yards

Weight:

0.00 kg 0.00 lbs

Number of Bags:

40LB: 0 bags 60LB: 0 bags 80LB: 0 bags

Estimated Price:

$0.00

Calculation Details

Volume Formula: V = Length × Width × Thickness

Current calculation: V = 0 × 0 × 0 = 0

Frequently Asked Questions About Concrete Calculation

What is the typical density/weight of concrete?

Normal concrete: approximately 150 lb/ft³ (2,400 kg/m³), lightweight concrete: approximately 115 lb/ft³ (1,840 kg/m³), heavyweight concrete: approximately 180 lb/ft³ (2,880 kg/m³) or more. Our concrete calculator uses a default density of 2,130 kg/m³. If your concrete has a different density, you can click the dropdown button next to the density setting to modify it to your required value. Weight calculations will update in real-time based on your custom density setting.

How many concrete bags per cubic foot/yard?

1 cubic foot requires 3.34 bags (round to 4) of 40lb concrete mix, 2.5 bags (round to 3) of 60lb concrete mix, and 1.67 bags (round to 2) of 80lb concrete mix. Our concrete calculator automatically displays the exact number of bags needed for 40lb, 60lb, and 80lb bag sizes, eliminating the need for manual calculations and rounding.

How do I measure irregular or complex shapes?

For complex shapes, break them down into simpler geometric forms (rectangles, circles, triangles) and calculate each section separately, then add the volumes together. For curved areas, use the average width method. Our concrete calculator includes a convenient "Add to Total" feature that allows you to calculate each section individually and automatically combine the volumes, weights, and prices. Simply click the "Add to Total" button after calculating each section, and the calculator will maintain a running total of all your project components.

How much extra concrete should I order?

We recommend ordering a little extra, because coming up short can be costly (small load charges, labor wait times, etc.). A rule of thumb is to add 4% to 10% to your concrete calculation to account for volume changes.

What's the difference between cubic feet, cubic yards, and cubic meters?

Based on construction standards: 1 cubic yard = 27 cubic feet = 0.764555 cubic meters. Most concrete in the US is sold by the cubic yard, while international projects use cubic meters. Our concrete calculator supports all these units for accurate volume calculations.

What are common concrete thicknesses for different projects?

Sidewalks: 4 inches (10 cm)
Driveways: 4-6 inches (10-15 cm)
Patios: 3-4 inches (8-12 cm)
House slabs: 4-6 inches (10-15 cm)
Garage floors: 5-6 inches (12-15 cm)
Commercial slabs: 6+ inches (15+ cm)

Free Online Concrete Calculator - Calculate Volume, Weight, Cost and Bags

Choose Concrete Structure Type

Slabs, Footings,Walls

Columns,Circular Slabs

Tubes,Post Holes

Curb And Gutter

Stairs

Ramps

Calculator main body

Slabs, Footings, Walls Calculation

Columns, Circular Slabs Calculation

Footing Calculation

Round Footing Calculation

Columns, Circular Slabs Calculation

Tubes, Post Holes Calculation

Curb And Gutter Calculation

Post Hole Calculation

Stairs Calculation

Ramps Calculation

Calculation Results

Advanced Settings

Calculation Details

Frequently Asked Questions About Concrete Calculation

What is the typical density/weight of concrete?

How many concrete bags per cubic foot/yard?

How do I measure irregular or complex shapes?

How much extra concrete should I order?

What's the difference between cubic feet, cubic yards, and cubic meters?

What are common concrete thicknesses for different projects?

QR Code

Slabs, Footings,
Walls

Columns,
Circular Slabs

Tubes,
Post Holes