Spike's Calculators

Calculate the amount of concrete needed in cubic feet and cubic yards for a slab in the shape of a circle.

To calculate the concrete volume needed for this type of slab, you need to know the circle's diameter and the depth of this slab..

A = π * D² ÷ 4

P = π * D

V = π * D² ÷ 4 * (d ÷ 12)

where A is the area in square feet, p = 3.14159265358979, D = diameter of circle P is the perimeter in lineal feet, p = 3.14159265358979, D = diameter of circle V is the volume in cubic feet, p = 3.14159265358979, D = diameter of circle, d = depth of slab in inches ÷ 12 converting this to feet

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

Diameter of slab = 12 feet depth of slab = 4 inches

Calculate the area in square feet using the Area formula;

3.14159 * 12² ÷ 4 = 3.14159 * 144 ÷ 4 = 113.1 (rounded to one digit)

The area of the slab is 113.1 square feet

Calculate the circumference (perimeter) of this slab using the Perimeter formula;

3.14159 * 12 = 37.6 (rounded to one digit)

This slab has a circumference of 37.7 feet

Calculate the amount of concrete you need for this slab using the Volume formula;

3.14159 * 12² ÷ 4 * (4 ÷ 12 ) = 3.14159 * 144 ÷ 4 * 0.333 = 37.7 (rounded to one digit)

The volume of this slab is 37.7 cubic feet

- enter the diameter of the slab in feet and inches
- slab depth in inches

- the area of the slab calculated in square feet
- the circumference (perimeter) of the slab in feet
- amount of concrete needed in cubic feet
- concrete needed in cubic yards
- concrete needed in cubic metres

- Circle
- Circle - Metric
- Donut
- Donut - Metric
- Ellipse
- Ellipse - Metric
- Equilateral Triangle
- Equilateral Triangle - Metric
- Octagon
- Octagon - Metric
- Oval
- Pentagon
- Pentagon - Metric
- Scalene Triangle
- Scalene Triangle - Metric
- Stadium Shape
- Stadium Shape - Metric
- Trapazoid
- Trapezium
- Plastic Concrete Footing Form