Concrete Calculator
Free online concrete calculator for slabs, columns, footings, and tubes. Calculate concrete volume in cubic meters, cubic yards, and cubic feet. Estimate weight and material needed for construction projects.
Slabs, Square Footings, or Walls
Hole, Column, or Round Footings
Circular Slab or Tube
Curb and Gutter Barrier
Stairs
What is a Concrete Calculator?
A Concrete Calculator is an essential construction tool that helps estimate the volume and weight of concrete needed for various structural elements. It supports multiple shapes including rectangular slabs, cylindrical columns, and hollow tubes. By entering dimensions and quantities, you can quickly determine material requirements, reducing waste and ensuring you order the correct amount of concrete for your project.
Types of Concrete Shapes
- Slabs, Footings, and Walls (Rectangular): Used for flat surfaces like floors, walls, foundations, and square footings. Volume is calculated as length × width × thickness.
- Columns and Round Footings (Cylindrical): Used for circular columns, round footings, and holes. Volume is calculated using the cylinder formula: π × radius² × height.
- Tubes and Circular Slabs (Hollow Cylinder): Used for hollow structures like tubes, pipes, and circular slabs with holes. Volume is calculated as π × (outer radius² - inner radius²) × height.
- Curb and Gutter Barriers: Used for roadside curbs with gutter channels. Volume is calculated by adding the curb rectangular section and the gutter flat section: (curb depth × curb height + gutter width × flag thickness) × length.
- Stairs: Used for concrete stairways. Volume is calculated by summing the individual step volumes plus the platform: each step increases in volume, creating a stepped structure.
Volume Formulas
Rectangular Slab:
V = L × W × H
Cylinder (Column):
V = π × r² × h
Hollow Cylinder (Tube):
V = π × (R² - r²) × h
Tips for Using Concrete Calculator
- Always add 5-10% extra concrete to account for spillage, uneven ground, and over-excavation
- Ensure all measurements are in the same unit or use the unit converter provided
- For irregular shapes, break them down into multiple simple shapes and calculate separately
- Standard concrete density is approximately 2,400 kg/m³ (150 lb/ft³)
- Round up to the nearest bag or cubic yard when ordering concrete
- Consider weather conditions - concrete sets differently in hot vs. cold weather
- Always verify measurements on-site before ordering concrete
About Concrete
Concrete is a composite material consisting of coarse aggregates (sand, gravel, crushed stone) bonded together with cement and water. Portland cement is the most common type used in construction. The concrete mixture must be placed before it hardens, typically within 90 minutes of mixing. Proper curing is essential - concrete reaches over 90% of its final strength in about 28 days. Common applications include foundations, slabs, walls, columns, driveways, and structural elements in buildings and infrastructure.