Coverting to cubic feet

Hello,

I am trying to determine how many bags of quickrete stucco mix I need to purchase.

One 80lb bag covers an area of approximately 0.83 cubic feet.

I have approximately 36 square feet of area to cover and my first coat of stucco needs to be 3/8" thick.

I understand that technically I can't convert square feet to cubic yards (the extra dimension issue) but is there a way to convert a fraction of an inch to a decimal of a foot so to use the formula for cubic feet on your web site.

Tom

[Robert Fogt]

Fractions are just division. 3/8 inch would be 3/8 or 0.375 on your calculator.

But you can use the length conversion page to convert fractions. So convert 3/8 from inches to feet on the length conversion page.

3/8 inch = 0.03125 feet

So now you have all units in feet:

36 square feet * 0.03125 feet = 1.125 cubic feet

Now to calculate how many bags you'd need.

1.125 cubic feet / 0.83 cubic feet/bag = 1.36 bags

So you would need two bags.

Thank you for the math lesson.

I was about to buy a whole lot more than two bags of quickrete.

I am humbled.

Tom67

I am off to purchase my stucco mix but and I was practicing the formula to determine the number of bags I need to purchase and a question came up.

When the cubic feet of my project was calculated (1.125 cubic feet) why wouldn't this figure be multiplied by the cubic feet per bag (0.83)?

I know that the formula calls for division but it's almost begging to be multiplied which would have me purchasing only one bag of quickrete.

Is there a layman's answer to this?

Tom 67

[Robert Fogt]

It's algebra.

cubic feet / cubic feet/bag = 1/(1/bag) = bag

cubic feet * cubic feet/bag = (cubic feet)²/bag = feet⁶/bag

Notice in the first instance, the cubic feet cancel, and you are left with bag. In the second instance, nothing cancels and you're left with a 6 dimensional shape of some sort.

how would it work for soil?

i am trying to add fertilizer ammendments to garden soil and the ammendments say to add 1 teaspoon per SQUARE foot. but i am planting in store bought soil that comes in CUBIC feet. therefore, how do i convert square feet to cubic feet? i dont want to add too much and/or to less fertilizer to my plants.
your help is much appreciated.

-Chris

peaceness01@hotmail.com

[Robert Fogt]

You just need to know how thick you are spreading the soil.

Hi Robert,

i am planting in 45 gallon pots. each pot holds 5 cubic feet of potting soil. as far as thickness, the pots stand about 18-24 inches tall. though i am not sure about the diameter. I am not sure if this is suffecient enough info though to do the calculations.

Thanks again.

-Chris

[Robert Fogt]

It doesn't really make sense that they listed the instructions in square feet.

Unless you just add the fertilizer to the top of the soil, then you just need the surface area of the pots.

To calculate the area of a circle, measure the diameter.

radius = diameter / 2
area = radius * radius * 3.14

If you measure the diameter in inches, the area will be in square inches. Then just convert that to square feet.

i need to know the formula to convert to cubic feet.
Firstly, how much cubic feet will a 20 foot container hold?

If i had 10 skids. 48x42x48, would they fit in a 20 foot container?