Concrete Calculator

This concrete calculator estimates how much ready-mix or bagged concrete you need for a slab, sidewalk, pad or footing. It accounts for a waste percentage and converts the total into the three most common bag sizes so you can buy the right amount the first time.

Your answer

1.36
Cubic Yards (with waste)
Order: 1.5 yd³
80 lb Bags
62
60 lb Bags
82
40 lb Bags
123
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How it works

Formula

Cubic Feet = L × W × (Thickness ÷ 12) × (1 + Waste%) • Cubic Yards = Cu Ft ÷ 27 • Bags = ceil(Cu Ft ÷ yield) (80 lb ≈ 0.60 ft³, 60 lb ≈ 0.45 ft³, 40 lb ≈ 0.30 ft³)

Worked example

A 10 × 10 ft pad at 4 in with 10% waste = 33.33 ft³ × 1.10 = 36.67 ft³ → 1.36 yd³, or 62 × 80 lb bags.

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Frequently asked questions

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