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Posted by on September 21, 2007, 10:58 pm
On Fri, 21 Sep 2007 21:59:49 -0000, Big_Jake
>>
>>
>> > How many 60lb bags of pre-mixed concrete will I need to make a 4 foot
>> > by 4 foot sidewalk square at 4 inches thick? (16 sq.feet) I only
>> > found one web based calculator and it said I need almost 40 bags. That
>> > cant be right. Heck, the bags are close to 4 inches thick and they
>> > are larger than a square foot. Math is not my thing....
>>
>> This one says 12 bags;
>>
>> http://www.packagepavement.com/qk_concrete_calculator.html
>>
>> You may need an extra bag or two to allow for uneven ground.
>>
>> I used about 43 bags of the 80 lb size for a hole 3x3 feet and about 3 feet
>> deep.
>
>I get the same number. Maybe the OP calculated based on 16 CUBIC feet
>instead of 16 SQUARE feet at 4" thick. The math seems about right.
>
>JK
I have found it is faster to do these calculations in cubic inches if
you have one of those new fangled calculator things.
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