Concrete Calculator
Estimate the concrete volume your project geometry requires. Review calculated volume, a separate 10% planning allowance, approximate bag quantities, and normal-weight concrete weight.
Slab / Footing / Wall
Rectangular slabs, patios, footings, and walls
Volume Needed
1.23
calculated cubic yards
1.36 cubic yards with 10% allowance
33.33
cubic feet
Approximate bags with 10% allowance
82
60-lb bags
62
80-lb bags
Approximate normal-weight concrete
5,000 lbs (2.5 tons)
Calculated volume does not capture every field condition. Confirm the order quantity, mix, delivery minimums, and waste allowance with the supplier or contractor.
Share the calculated scope with contractors whose service area and specialty fit the project
How to Use This Concrete Calculator
This concrete calculator estimates the volume and weight of concrete necessary to cover a given area. It supports five common shapes used in residential concrete projects.
Supported Shapes
- Slabs, Footings & Walls - Rectangular pours for patios, driveways, foundations, and retaining walls.
- Columns & Round Footings - Cylindrical pours for deck posts, fence posts, and pier footings.
- Circular Slabs & Tubes - Hollow cylinder shapes for pipe encasements and circular foundations.
- Curb & Gutter - L-shaped cross-sections for roadside barriers and drainage channels.
- Stairs - Stepped structures with uniform rise and run dimensions.
Tips for Ordering Concrete
- The tool shows a separate 10% planning allowance. Confirm the appropriate order allowance with the supplier or contractor because subgrade variation, forms, placement method, and waste differ.
- Ready-mix pricing is not calculated. Local suppliers may apply mix, delivery, short-load, waiting-time, fuel, pumping, and minimum-order charges.
- Pre-mixed bags (60-lb or 80-lb) are ideal for smaller jobs like fence posts or small repairs.
- Enter the thickness from the project scope. Intended use, loads, support, edges, drainage, local requirements, and design responsibility can change the required section.
Need Professional Help?
Once you know how much concrete your project requires, the next step is defining the installation scope. Contractors for Concrete can check for contractor matches based on your project type and location. Independently verify credentials, insurance, references, and contract terms before hiring.