# conversion for sq. ft to yards of concrete



## shazamyman

how do you figure your yardage for concrete in an area...


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## Double-A

Area = length x width
Volume = length x width x height (or depth of concrete)

To convert cubic feet to cubic yards, divide by 27.

One yard = 3 feet

3'x3'x3' = 27 cubic feet =1 cubic yard.

Now, having said all that, if this is the first time you're ordering concrete, you might want to get someone with some experience in to help and double check your numbers.

You don't work concrete, it works you. Plus, it never forgets... Sorta like a wife.


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## neolitic

SSSSSh!:shifty:Come closer, it's a secret!:shifty:
(Fourth grade math. Keep it under your hat!):shifty:


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## neolitic

AAAAh! 
*Snoopy* is a blabber mouth!


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## shazamyman

Double-A said:


> Area = length x width
> Volume = length x width x height (or depth of concrete)
> 
> To convert cubic feet to cubic yards, divide by 27.
> 
> One yard = 3 feet
> 
> 3'x3'x3' = 27 cubic feet =1 cubic yard.
> 
> Now, having said all that, if this is the first time you're ordering concrete, you might want to get someone with some experience in to help and double check your numbers.
> 
> You don't work concrete, it works you. Plus, it never forgets... Sorta like a wife.


 

ive ordered and poured myself before, but its been a while.

ive got a gargae addition and ive got the exreience to pour the job myself, i just cant remember 


so....an area 25 long ft x 30 wide ft x 6 inches deep is 16.6 yards of crete? that seems like a bit much


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## Forry

25x30=750 sq'
750/2=375 cu' ('caus its 6" deep div by 2)
375/27=13.88 yds

call it 14 1/2 'caus I like extra



How'd you get 16.6?


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## concretemasonry

25' x 30' x 6" (1/2 foot) is 375 cubic feet.

divided by 27 is 13.88888 cubic yards, so order about 15 yards since you grades may not be exact. - Mkae sure you have sidewalk or something else poured so you have a place to put the excess. They usually do not like to take concrete back.


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## shazamyman

Forry said:


> 25x30=750 sq'
> 750/2=375 cu' ('caus its 6" deep div by 2)
> 375/27=13.88 yds
> 
> call it 14 1/2 'caus I like extra
> 
> 
> 
> How'd you get 16.6?


 
i followed this formula
Area = length 30 x width 25 =750
Volume = length 30 x width 25 x height .6 =450 / 27 = 16.6


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## Double-A

neolitic said:


> AAAAh!
> *Snoopy* is a blabber mouth!


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## neolitic

Double-A said:


>


:laughing::lol::laughing:


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## reveivl

Height is 0.5 not 0.6


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## Chris Johnson

Now...who knows how many meters are needed...:laughing::laughing::laughing:


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## shazamyman

reveivl said:


> Height is 0.5 not 0.6


 
irealized that earlier, so what would it be if it were four incehs?

i have to ask you to excuse me, i have a ninth grade education, but ive got 15 years hands on experience, and 2 years independent contractors experience, ive only done 2 pours on my own and they were small porches...


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## shazamyman

Chris Johnson said:


> Now...who knows how many meters are needed...:laughing::laughing::laughing:


 

 now my brains startin to hurt


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## Tscarborough

My ninth grader is doing calculus (that I can't do), but the answer is to divide the little number by the big number, i.e. 4 divided by 12 = .33


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## neolitic

For all practical purposes:
1"=.08
2"=.17
3"=.25
4"=.33
5"=.42
6"=.5
7"=.58
8"=.67
9"=.75
10"=.83
11"=.92
12"=1


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## Forry

Neo, did you do that all by yourself? Or did you ask T's 9th grader for a formula? Just razzin'.

Revievl's right, 6" is half a foot (a foot is 12", so half that is, well .5). Easy mistake to make. Got a friend who uses a slide rule kinda thingie her concrete guy gave her... put in length x width x depth and you get the right order off the thing, but I like doing it the "hard" way. 

For a 4" slab do length x width x (neo table). Divide by 27 than add some, round up, or add more if you're not sure of the grading. My concrete provider will take it back if I order too much, but they charge me for it 'cause it's junk if it's not used.


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## neolitic

Forry said:


> Neo, did you do that all by yourself? Or did you ask T's 9th grader for a formula? Just razzin'.


Long ago,
In a galaxy far far away.....
I was a field engineer, 
i.e. building layout and
site work.
Dimensions and grades are all
in feet, 10ths, and 100ths.
Stuff is engraved in the 
lizard brain. Handy when doing math
with measurements to the 8th!


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## Forry

Sure 'nuff


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## Joasis

There are calculators online like this one: http://www.concretenetwork.com/concrete/howmuch/calculator.htm

Makes things easy to the exact decimal. Footings also. 

Now, when I am roughing out an estimate, we figure 80 square feet of concrete to the cubic yard if it is a 4 inch slab....60 sq/ft for 6 inch slabs.


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