Amount of concrete needed for piers

[youngins]

How many pounds of quickcrete would you budget for 6 piers, each 6" in diameter and 18 inches deep?

Thanks

Chris

[peg_688]

My guess is close to a whole bag(60lbs) per hole.  A bag cost what under $3.00 around here , so I get 6 , it might only take 5 but the trip back to pick up one bag of redimix can be pretty fustrating.  

[MikeT]

Well, according to the online calculator at decks.com
http://www.decks.com/calculators/concrete.aspx

You would need:
Cubic Feet Required:        1.77        
Cubic Yards Required:       0.07       
Number 60 lb Bags:       3.5       
Number 80 lb Bags:       2.7