The Standard size of the 1st class brick is 190 mm × 90 mm × 90 mm and with mortar joint should be 10 mm thick. So, brick with mortar = 200 × 100 × 100 Volume of 1st class brick with mortar = 0.2 × 0.1 × 0.1 = 0.002 cu.m No. of bricks per 1cu.m = 1/volume of 1st class brick with mortar = 500 no's of bricks