A 28mm TMT bar weighs 4.834 kg per metre, calculated with the d²/162.2 formula: (28 × 28) ÷ 162.2 = 4.834 kg/m.
A standard 12 m length of 28mm TMT weighs 58.01 kg (4.834 kg/m × 12 m).
Approximately 17 standard 12 m bars of 28mm TMT make one tonne (1,000 ÷ 58.01 kg per bar). Actual counts vary with rolling tolerance under IS 1786.