Quantity of bricks depends upon:

 Size of Bricks

 Thickness of wall
 Thickness of mortar
So, Let’s calculate the required bricks for 1000 ft² in two cases by taking two size of bricks.
CASE 1:
Size of brick= 8”x4”x4”
Thickness of mortar = 0.4 “
Thickness of Wall = 9”
No. of bricks = Volume of brickwork/ volume of 1 brick with mortar
Volume of 1 Brick with mortar = 8.4”x4.4”x4.4” =162.624 inch^3.
Volume of brickwork = Thickness of wall x Area of brickwork
Volume of brickwork = 9”x 144”=1296 inch^3 (∵1sq.ft=144”)
∴ No. of bricks in 1 sq.ft = 1296/162.624 = 7.969
Bricks required for 1000 sq.ft = 7969
Consider the wastage percentage as 10 %
Then, No. of bricks including wastage = 8766 No’s
If, Thickness Of Wall = 4.5”
Then, No. of bricks = 3985 No’s
Consider the wastage percentage as 10 %
No. of bricks including wastage = 4383 No’s
CASE 2:
Size of brick = 9”x4.5”x3”
Thickness of mortar = 0.4 “
Thickness of wall = 9”
No. of bricks = Volume of brickwork/ volume of 1 brick with mortar.
Volume of 1 Brick with mortar = 9.4”x4.9”x3.4” = 156.604 inch^3.
Volume of brickwork = 9”x 144”=1296 inch^3 (∵1sq.ft=144”)
∴ No. of bricks in 1sq.ft = 1296/156.604 = 8.27 No’s
Bricks required for 1000 sq.ft = 8270 No’s
Consider the wastage percentage as 10 %
Then, No. of bricks including wastage = 9097 No’s
If, Thickness of Wall = 4.5”
Then, No. of bricks = 4135 No’s
Consider the wastage percentage as 10 %
No. of bricks including wastage = 4549 No’s
Watch the video in the below link for better understanding and detailed explanation.