Weight Estimations
Plywood
3 lbs/sqft per inch of thickness (APA Plywood Design Specification)
Example:
Length: 12 inches
Width: 12 inches
Thickness: 1/4 inches
144 sqin in a sqft
Formula:
Weight = $3 * (L x W)/144 * T
Weight = $3 * (12 x 12)/144 * 0.25
Weight = 0.75 lbs
Concrete
The weight of concrete differs based on the materials used. In some cases concrete is injected with materials to intentionally make it stronger, lighter, cure faster. Those variables may have an impact on the weight. for a rough estimation we'll use 145 lbs/ft3. Since our projects are rather small we will use the formula 145/12^3 so we have the lbs per cubic inch.
0.084lbs/cuin
Example:
I have a box I need to fill with concrete.
Length: 24"
Width: 12"
Height: 4"
Formula:
Weight = 0.084 * L * W * H
Weight = 0.084 * 24 * 12 * 4
Weight = 96lbs
Sources
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