CostimexFree tool
Concrete Volume Calculator
Estimate cubic yards or cubic metres of concrete for slabs, footings and pads — with waste factor built in.
Tip: a 5–10% waste factor accounts for spillage, over-excavation and pump losses.
Concrete needed
2.72 yd³
≈ 2.08 m³
Raw volume
2.47 yd³
before waste factor
60 lb bags
163
premix bags (approx)
FAQ
Common questions
How accurate is this concrete calculator?+
It returns the geometric volume plus your chosen waste factor. Actual pour can vary by 5–10% depending on subgrade variation, formwork over-excavation and slump losses.
What waste factor should I use for concrete?+
Use 5% for tightly formed footings, 7–10% for slabs on grade, and 10–15% for pump pours, hand-dug footings or irregular shapes.
How many bags of concrete do I need?+
The calculator estimates 60 lb bags (~0.45 cuft each) and 25 kg bags (~0.0125 m³ each). For pours over ~1 m³ ready-mix is almost always cheaper than bags.
What's the difference between cubic yards and cubic metres?+
1 cubic yard = 0.7646 m³; 1 m³ = 1.308 yd³. The US uses yd³, the UK/EU uses m³. Switch the unit toggle above for either.
Does this include rebar or formwork?+
No — this is concrete volume only. Use our Rebar Calculator for steel quantities, and budget formwork separately at typically 8–15% of concrete cost.
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