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Concrete Slab Yardage Calculator

Enter slab length, width, and depth to get cubic yards + bag count with waste.

Where this fits

📦 Business & Seller OpsGoing 1099FreelancersFounders

This tool lives inside Going 1099 and is most useful for freelancers and founders.

Corp Tax Rate21%
SE Threshold$400
FICA Cap 2024$168,600

Slab Dimensions

Cubic yards
2.72
with waste
Coverage
200 sq ft
4" thick
60-lb bags
163
if mixing by hand
80-lb bags
123
if mixing by hand

Quick reference

Slab area200 sq ft
Cubic feet66.67 cu ft
Cubic yards (net)2.47 cu yd
Waste0.25 cu yd (10%)
Order quantity2.72 cu yd
1

Slab area

area = length × width

= 20 ft × 10 ft

= 200.00 sq ft

2

Cubic feet of concrete

cu ft = area × (depth ÷ 12)

= 200.00 × (4 ÷ 12)

= 66.67 cu ft

Depth is in inches; divide by 12 to convert to feet

3

Cubic yards (no waste)

cu yd = cu ft ÷ 27

= 66.67 ÷ 27

= 2.47 cu yd

There are 27 cubic feet in 1 cubic yard

4

Waste factor

waste = cu yd × waste%

= 2.47 × 10%

= +0.25 cu yd

10% waste is standard; steep forms or complex shapes may need 15%

5

Total with waste

total = cu yd × (1 + waste%)

= 2.72 cu yd

Order this amount from your ready-mix supplier

Key insight

Rule of thumb: 1 cubic yard covers 81 sq ft at 4 inches thick. Always order slightly more than calculated — short pours leave cold joints that weaken the slab.

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