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CONCRETE

Concrete Slab Calculator

Find how many cubic yards of concrete a slab or pour needs and the material cost at your local ready-mix price.

JOB INPUTS

Enter your numbers

Loading saved values

Slab length in feet

ft
Slab length in feet

Slab width in feet

ft
Slab width in feet

Slab thickness in inches

in
Slab thickness in inches

Ready-mix concrete price per cubic yard

$
Ready-mix concrete price per cubic yard
Results update automatically
CALCULATED RESULTUSD
Concrete needed2.47 yd³
Cubic yards2.47 yd³
Cubic feet66.67 ft³
Material cost$370.37
Cost per sq ft$1.85
FORMULA USED20 ft × 10 ft × 4 in ÷ 12 = 66.67 ft³ ÷ 27 = 2.47 yd³ × $150.00 = $370.37

HOW TO USE IT

How to use the Concrete Slab Calculator

  1. 1

    Enter the slab length and width in feet.

  2. 2

    Set the slab thickness in inches.

  3. 3

    Enter the ready-mix price per cubic yard.

  4. 4

    Review cubic yards needed and the material cost.

THE MATH

Concrete volume formula

Cubic feet = length × width × (thickness ÷ 12); cubic yards = cubic feet ÷ 27

Ready-mix concrete is sold by the cubic yard (27 cubic feet). The calculator converts the slab volume to cubic yards and multiplies by your local price per yard.

PRACTICAL EXAMPLE

A 20 × 10 ft slab, 4 in thick

A 20 × 10 ft slab at 4 inches is about 66.7 cubic feet, or 2.5 cubic yards. At $150 per cubic yard, the concrete material is about $375.

FAQ

Frequently asked questions

How many cubic feet are in a cubic yard?

27 cubic feet. Divide the total cubic feet by 27 to get cubic yards.

How much concrete does a 4-inch slab need?

Each 100 sq ft of a 4-inch slab is about 1.23 cubic yards. Use the calculator with your exact dimensions for a precise number.