A 16mm TMT bar weighs 1.578 kg per metre, calculated with the d²/162.2 formula: (16 × 16) ÷ 162.2 = 1.578 kg/m.
A standard 12 m length of 16mm TMT weighs 18.94 kg (1.578 kg/m × 12 m).
Approximately 52 standard 12 m bars of 16mm TMT make one tonne (1,000 ÷ 18.94 kg per bar). Actual counts vary with rolling tolerance under IS 1786.