 The specific heat of a substance (per unit of mass) has dimension L2·Θ−1·T−2, or (L/T)2/Θ.Therefore, the SI unit J/K/kg is equivalent to metre squared per second squared per kelvin (m2 K−1 s−2).Professionals in construction, civil engineering, chemical engineering, and other technical disciplines, especially in the United States, may use the so-called English Engineering units, that include the Imperial pound (lb = 0.45459237 kg) as the unit of mass, the degree Fahrenheit or Rankine (°F = 5/9 K, about 0.555556 K) as the unit of temperature increment, and the British thermal unit (BTU ≈ 1055.06 J), as the unit of heat.