concrete measuring

to find the ammount needed: length in feet x width in feet x thickness in ft + cubic feet divided by 27 to get cubic yards, which is the measure used when buying ready mixed concrete.

example 20 ft by 40 ft by 4 inches thick:

20x40x.33= 264 cubic feet divide by 27 = 9.78 cubic yards. IN this case you would order 10 yards as concrete is sold in yard increments.

JMHO

Carl