HOW TMT BARS SECTION WEIGHT/UNIT WEIGHT CALCULATED?

It is important to know the section weight of steel tmt rod to arrive quantity of steel and to check the section weight of steel

here the formula is  πr2h multiplied by steel density

density of steel is 7850kg/m3

suppose i want to find the 16 dia steel tmt rod section weight, so 3.14"×",  .008 "×",.008"×",.001"×",7850

here comes the answer 1.58kg per metre.

so every time we have use this formula, no need a simple formula is dia square / 162, so use the formula for 16 dia , 16 ×16 / 162, THE ANSWER IS 1.58 KG/M3