`M = 1/2 *pi *r^2 *d*mD`

Enter a value for all fields

The Weight of a Semi-circle Concrete Slab calculator computes the weight or mass of a semicircular shaped concrete slab based on the radius (r), the depth (D) and mean density of concrete.

INSTRUCTIONS: Choose units and enter the following:

• (d) Depth of Semi-circle slab
• (r)  Radius of the semi-circle slab

Semi-circle Mass (M):  The calculator returns the weight in pounds.  However, this can be automatically converted to compatible units (e.g. kilograms, tons, metric tons) via the pull-down menu.

The Math / Science

The formula for the volume of a semicircle is:

       M = ½•π•r²•d

where:

• M = Mass or weight of semi-circular concrete slab 
• d = Depth of Slab
• r = radius of the semicircle

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Circular Concrete Slab Calculators

• Rebar in Circular Slab: Computes the length and weight of rebar in a circular slab based on the dimensions, spacing, number of mats, rebar size, rebar stick length and lapping factor.
• Circular Slab Surface Area: Computes the surface area of a circular slab based on the diameter.
• Circular Slab Circumference: Computes the perimeter (circumference) of a circular slab base on the diameter.
• Volume of Circular Slab: Computes the cubic yards (volume) of concrete a circular slab based on the diameter and depth.
• Circular Slab Weight: Computes weight of a circular slab of concrete based on the diameter, depth and the mean density of concrete.
• Circular Slab Circumference from Area: Computes the circumference of a circular slab based on the surface area of the slab.
• Semi-circle Slab Volume: Computes the volume of concrete in a semicircular shaped slab based on the radius and the depth.
• Semi-Circle Slab Weight: Computes the weight or mass of a semicircular shaped concrete slab based on the radius, the depth and mean density of concrete.

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Concrete Slab Calculators

The following functions apply to estimating the amount of concrete, rebar, form boards and water needed for concrete slabs of different shapes: rectangular with squared corners, circular including semi-circle, and polygon shapes from triangular up (e.g., pentagon for 5 sides and dodecagon for 12 sided polygon).

Rectangle Slab

• Rebar and Concrete in a Slab: Computes the total length and weight of rebar and the volume and weight of concrete needed for a rectangular slab, taking into account the concrete displaced by the rebar.
• Concrete in Rectangle Slab: Computes the volume of concrete in a rectangle (squared corners) slab based on the dimensions.  It includes the volume of concrete in cubic yards and the equivalent volume in bags of concrete.  It also includes the surface area, length of form boards, and the water requirement. 
• Slab Weight: Computes the weight, volume of concrete and surface area of a rectangle slab based on the length, width and depth of the concrete of the slab and the density of concrete.
• Weight of Slab with Rebar: Computes the weight of a rectangle slab with rebar based on the length, width and depth of the concrete of the slab, the density of concrete and the size and spacing of rebar.  It includes total weight (concrete and rebar), and the contribution of weight from rebar and concrete separately.
• Slab Area and Perimeter: Compute the surface area and perimeter of a rectangular slab based on the dimensions.

Circular Slab

• Volume of Circular Slab: Computes the slab surface area, perimeter and cubic yards of concrete in a circular slab based on the diameter and depth.  It also provides, the equivalent volume in 80lb, 60lb and 40lb bags of concrete and the water requirement.
• Circular Slab Weight: This computes the weight of the concrete in a circular slab based on the diameter, depth and density of concrete.
• Rebar and Concrete in a Circular Slab: This computes the length and weight of rebar in a rectangular slab.  It also computes the total weight of the slab including concrete, taking into account the concrete displaced by rebar.
• Semi-Circle Slab Volume: Computes the volume of concrete needed for a semi-circular slab based on the radius and depth.
• Semi-Circle Slab Weight: Computes the weight of concrete in a semi-circular slab based on the radius, depth and density of concrete.

Polygon Slab

• Concrete in Polygon Slab: Computes the surface area and cubic yards of concrete for a polygon slab based on the dimensions and depth.  It also provides the equivalent volume of concrete in 80lb, 60lb and 40lb bags of concrete.

General Functions

• Concrete Weight: Computes the weight of a specified volume (e.g., 2.3 cubic yards) of concrete.
• Price of Delivered Concrete: Computes the price of delivered concrete based on the volume, price per cubic yard, pumping cost, delivery distance, and mileage.
• Water Needed for Concrete: Compute the amount of water needed to make a volume of concrete.
• Concrete Displaced by Rebar: Computes the volume of concrete displaced by a length of rebar based on the length and size of rebar.