Concrete Calculator

Estimate how much concrete you need for slabs, footings, columns, curbs and stairs — with weight, bags, trucks and cost.

Concrete to order
0yd³

Pre-mixed bags needed

DIY mix materials
How this is calculated
  • Volume is worked out from your dimensions, multiplied by quantity, then increased by the waste allowance to cover spillage, uneven subgrade and over-excavation.
  • Bag yields: about 0.0075 ft³ per lb of dry mix (80 lb ≈ 0.60 ft³, 60 lb ≈ 0.45 ft³, 50 lb ≈ 0.375 ft³, 40 lb ≈ 0.30 ft³).
  • Stairs are treated as solid: each step is as tall as the steps below it, with the platform poured at full height.
  • Curb & gutter cross-section = curb depth × curb height + gutter width × flag thickness, multiplied by length.
  • DIY mix uses a dry-volume factor of 1.54, cement at 1,440 kg/m³ and a 0.5 water-to-cement ratio.
  • These are estimates. Always confirm quantities with your supplier or engineer before ordering.
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