Hmmm, with a cube 1x1x1 m I get: 35.315 cubic feet or 1.308 cubic yards or 1.000 cubic meters if pre-mixed concrete*, it is 4696.851 lbs or 2130.000 kgs if 6

Hmmm, with a cube 1x1x1 m I get: 35.315 cubic feet or 1.308 cubic yards or 1.000 cubic meters if pre-mixed concrete*, it is 4696.851 lbs or 2130.000 kgs if 60 lbs per bag, it is 78.281 bags if 80 lbs per bag, it is 58.711 bags The 2130 Kg/mc may be arbitrary, and, to be picky: 60x78.281x0,454= 2132,37444 still the (as well arbitrary) "adding 10% to allow for spillage and slab depth variations" seems like having been forgotten.