Spike's Calculators

Calculate the amount of concrete needed for a slab using feet and inches for measurements. This calculator provides results in cubic feet, cubic yards and cubic metres.

- enter the length of the slab in feet and inches
- the width of the slab in feet and inches
- thickness of the slab inches

- square footage of the slab
- amount of concrete needed in cubic feet
- concrete needed in cubic yards
- concrete needed in cubic metres

one cubic inch (in³) = 0.000578703703703704 cubic feet (ft³) one cubic inch (in³) = 0.0000214334705075445 cubic yards (yd³) one cubic inch (in³) = 0.000016387064 cubic metres (m³)

To convert cubic feet to cubic yards, multiply cubic feet * 0.037037037037037 To convert cubic feet to cubic metres, multiply cubic feet * 0.028316846592 To convert cubic yards to cubic metres, multiply cubic yards * 0.764554857984

slab length = 25' width = 12'-8" concrete slab thickness = 6"It all has to be in the same units. It would be possible to change it all into inches, but that makes for large numbers so it will be easier to convert the inches into a foot value.

12'-8" convert 8 inches into feet by dividing by 12

8 ÷ 12 = 0.666 feet12'-8" then becomes 12.666 feet

Next convert the 6" into a foot value by dividing this amount by 12

6 ÷ 12 = 0.5 feetNow you can fractions the concrete volume for this slab by multiplying the length, width and depth values together.

25 * 12.666 * 0.5 = 158.325 cubic feetYou will need 158.3 cubic feet of concrete for this slab

Usually, the cost for the concrete is for a price per cubic yards or cubic metres.

To change cubic feet to cubic yards: There are 27 cubic feet in one cubic yard. Divide your cubic feet amount by 27 to get to the cubic yard volume of concrete.

158.325 ÷ 27 = 5.86 cubic yards.

- Circle
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- Scalene Triangle - Metric
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