how much premix cement is in a bag?

Answer 1

Redimix concrete typically comes in 80 or 60 lb bags. A 60 lb bag is easier to handle, but the 80 lb is usually a better deal money wise. An 80 lb bag provides about 0.6 cubic feet of cured concrete. A 60 lb bag provides about 0.45 cubic feet. For reference, there are 3600 lbs of dry concrete mix in a cubic yard (27 cubic feet), so divide the total cubic feet of concrete needed by the cubic feet shown above for each bag size in order to determine how many bags you will need.

For 1 cubic yard of concrete you would need:
with 80 lb bags = 45 bags
with 60 lb bags = 60 bags

Answer 2

Depends on the kind you by. I think a standard bag is 80 lbs. and makes a little over a half of a cubic foot of concrete. Some of the quick mixes and such are smaller. I've seem some of the fast cure and post mix stuff in 40 lb. bags.