[Fix'n it]

i will be patching this in a few weeks. that is 3" pipe. the original slab is about 1"- 1-1/2" thick. its about 1' wide and about 5' long. i will fill this whole and tamp it down, leaving about 1 1/2 for the cement.

 

[joecaption]

http://www.calculator.net/concrete-calculator.html
Have an extra bag on hand.
Cheap insurance.

 

[joed]

5'x1'x2" is .8 cubic feet. Check the bags for how much it contains.

 

[Red Squirrel]

My guess is about 1-2 bags. I always fall short, so make it 4.

The tools provided are probably better than my guess though. I should have used those myself when I poured.