How much Kg per cum for M40 cement will be?

M40 grade of concrete : is recommended in extreme exposure or when very heavy loads are to be carried (like pier of a bridge etc) Under extreme exposure - reinforced M40 grade concrete should have minimum cement = 360 kg/cubm. This can vary from 300 to 360 for exposures from mild to extreme. Plain M40 grade used under mild to extreme exposure has minimum cement content from 220 to 280 kg/cubm Other considerations like admixtures (fly ahs etc) and actual mix design is the best method of arriving at minimum cement contents.