How thick should a concrete slab be?

Standard residential slabs are 4 inches thick. Driveways and garages need 5-6 inches if heavy vehicles will park on them. Footings for walls typically require 8-12 inches.

How much extra concrete should I order?

Order 5-10% extra to account for uneven ground, spillage, and slight over-excavation. For complex shapes, go with 10-15%. Running short mid-pour creates a cold joint that weakens the structure.

How many bags of concrete per cubic yard?

One cubic yard requires approximately 45 bags of 80-lb concrete or 60 bags of 60-lb concrete.

Concrete Calculator

Figure out cubic yards, bags, and cost for slabs, footings, and columns.

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Slab Thickness Guide

Application	Minimum Thickness	Recommended
Sidewalk (foot traffic)	3.5 inches	4 inches
Patio	4 inches	4 inches
Driveway (passenger cars)	4 inches	5 inches
Garage floor	4 inches	5–6 inches
Driveway (heavy trucks)	5 inches	6 inches
Foundation footing	8 inches	10–12 inches