Concrete Calculators

Shapes and structures

Calculators for the basic forms: flat slabs, footings, columns, walls, stairs, curbs, round slabs, tubes, tube forms and post holes.

• Slab calculatorLength × width × thickness to yards and bags.
• Footing calculatorStrip or spread footings in yards and bags.
• Column calculatorRound or square columns, piers and footings.
• Wall calculatorPoured walls with door and window openings.
• Stairs calculatorSolid concrete steps with an optional landing.
• Curb and gutter calculatorCurb, gutter and flag from the cross-section.
• Circular slab calculatorRound pads, patios and fire pit bases.
• Tube calculatorPipes, rings, culverts and hollow cylinders.
• Sonotube calculatorConcrete and bags for round tube forms.
• Post hole calculatorBags per post for fences, decks and signs.

Common projects

Slabs with the defaults of a typical driveway, patio, sidewalk or equipment pad.

• Driveway calculatorDriveway yards, thickness and cost range.
• Patio calculatorPatio slabs sized to your furniture.
• Sidewalk calculatorWalkways by length, width and thickness.
• Pad calculatorPads for AC units, sheds and generators.

Bags, yards, weight and cost

Convert a volume to bags, yards or cubic meters, weigh it and price it.

• Bag calculatorHow many 40, 50, 60 and 80 lb bags.
• Yards calculatorSquare feet × thickness = cubic yards.
• Cubic meter calculatorMetric concrete volume in m³ with yd³ and ft³.
• Weight calculatorPounds, tons and kilograms for any volume.
• Cost calculatorCompare a truck with bags using your prices.
• Pallet calculatorPallets, loose bags and weight to haul.

Materials and reinforcement

Estimate the other materials that go with concrete.

• Block calculatorHow many CMU blocks a wall needs.
• Rebar calculatorBars, length and weight for a slab grid.
• Gravel base calculatorTons and yards of gravel under a slab.
• Mix ratio calculatorCement, sand and gravel for a volume.

Common slab sizes

Twelve frequently asked slab sizes, with yards, bags and weights for each thickness.

• 10×10 ft slabYards, bags and weight for a 10×10 ft slab.
• 12×12 ft slabYards, bags and weight for a 12×12 ft slab.
• 12×16 ft slabYards, bags and weight for a 12×16 ft slab.
• 12×20 ft slabYards, bags and weight for a 12×20 ft slab.
• 16×16 ft slabYards, bags and weight for a 16×16 ft slab.
• 20×20 ft slabYards, bags and weight for a 20×20 ft slab.
• 20×24 ft slabYards, bags and weight for a 20×24 ft slab.
• 24×24 ft slabYards, bags and weight for a 24×24 ft slab.
• 24×30 ft slabYards, bags and weight for a 24×30 ft slab.
• 30×30 ft slabYards, bags and weight for a 30×30 ft slab.
• 30×40 ft slabYards, bags and weight for a 30×40 ft slab.
• 40×40 ft slabYards, bags and weight for a 40×40 ft slab.

Frequently asked questions