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Concrete Calculator

Calculate cubic yards or cubic meters of concrete needed for slabs, footers, walls, or columns. Includes bag-count estimates for small jobs.

Inputs

Concrete needed (with 10% waste)
Cubic feet (raw)
Cubic meters (with waste)
60-lb bags needed
80-lb bags needed

About Concrete Calculator

When to order vs bag

Under ~1 cubic yard: use bags from a hardware store. 1-2 yards: borderline — bags are cheaper but a lot of mixing. Over 2 yards: order ready-mix delivery (typical minimum order 1-3 yd³).

Slab thickness guide

Sidewalks: 4". Driveways: 4-6". Heavy-vehicle pads / shop floors: 6-8". Footers: depends on local code, often 8-12" wide × 8-16" deep. Always check local frost-line depth for footers in cold climates.

Cure time

Concrete is walkable in 24-48 hr, light vehicle in 7 days, full strength at ~28 days. Keep moist (cover with plastic or wet burlap) during the first week for best strength. Don’t pour in freezing temps without special additives.