How to Calculate Weight of TMT Steel Bar Calculation of TMT bar Weight TMT bars are extensively used in building construction and hence, their weight becomes a subject of paramount importance. To discover the mass of steel per meter square, the exact formula is D*D/162. In this formula, D is the diameter of the bar in meters as well as the mass will be evaluated in kilograms. Here, W is known as the weight of the bar in kg, D is known as the diameter of the bar in mm, plus L in the length of the bar in meters. Calculation for the weight of a steel bar: Formula for weight of Steel bars = πD*2/ 4 × L × density, In the formula, w = weight of steel, π = 3.14, L= length of Steel bar =1m, D = diameter of Steel bar in mm in addition to density = 7850 kg/ m3. Calculation of TMT bar section weight: In case, we set 1 meter length for every diameter of steel bar in the formula then we will obtain the unit weight, here. 1. 6 mm ø bar = 6² x 1/162 = 0.222 kg per m. 2. 8 mm ø bar = 8² x 1/162 = 0.395 kg per m. 3. 10mm ø bar = 10² x 1/162 = 0.617 kg per m. 4. 12mm ø bar = 12² x 1/162 = 0.888 kg per m. 5. 16mm ø bar = 16² x 1/162 = 1.580 kg per m. Illustration: Weight of 12mm steel bar: For example , diameter of steel = 12mm, length of 1 steel rod = 12 meter, after that weight of 1 piece of 12mm steel rod in kilogram = (12×12×12)/162 = 10.667 kg. Thus, weight of 1 piece 12mm Steel rod is 10.667 kg. Weight of 1 TMT bar: TMT Steel Weight Chart: Diameter Number of Rods Weight