Convert Kilojoules per Kilogram to Joules per Kilogram

The Kilojoule per Kilogram (symbol: kJ/kg) is a unit of specific energy. A metric specific-energy unit equal to exactly 1,000 J/kg. kJ/kg is the dominant working unit in thermodynamics for specific enthalpy h, specific internal energy u, and specific Gibbs/Helmholtz free energies (g, a) — all standard symbols in IAPWS-IF97 steam tables, NIST REFPROP property libraries, and CoolProp Helmholtz-energy fluid models. Reference values: saturated liquid water at 100°C (1 atm): h_f = 419.04 kJ/kg; saturated steam at same point: h_g = 2,676.05 kJ/kg; the latent heat of vaporization h_fg = 2,257.0 kJ/kg (the energy a low-pressure steam-heating system delivers when condensing). Refrigerant R-134a saturated liquid at 25°C: h_f ≈ 234.6 kJ/kg; saturated vapor: h_g ≈ 412.4 kJ/kg. Outside the US, food energy content on nutrition labels is reported as kJ/100g per EU Regulation 1169/2011 and Codex Alimentarius (typical: cooked white rice ~540 kJ/100g; olive oil ~3,700 kJ/100g; lean beef ~880 kJ/100g). HVAC design and combustion calculations per ASHRAE / VDI 4710 / EN 12831 routinely use kJ/kg for moist-air psychrometric enthalpy.

It belongs to the metric measurement system.

Kilojoules per Kilogram are commonly used in fuel comparison, battery technology, and rocket propulsion.

The Joule per Kilogram (symbol: J/kg) is a unit of specific energy. The SI unit of specific energy (energy per unit mass) per ISO 80000-5 §5-15 — used for gravimetric energy density of fuels, batteries, explosives, and propellants. J/kg is the universal unit for cross-technology energy-storage comparisons, and the natural unit for kinetic-energy-per-mass (E_k/m = ½v² in J/kg = m²/s²). Reference values for energy-storage media per Sandia National Labs / DOE battery testing protocols and NFPA 921 fire-investigation reference data: lithium-ion 18650 cell ~550,000 J/kg (gravimetric); lithium-iron-phosphate (LFP, LiFePO₄) cells 360,000-450,000 J/kg; lead-acid battery 110,000-180,000 J/kg; gasoline 46,400,000 J/kg lower heating value (LHV) per ASTM D4868; diesel 45,500,000 J/kg LHV; coal (bituminous) ~24,000,000 J/kg; TNT 4,184,000 J/kg (the explosive-yield reference standard, basis of 'megaton' nuclear yield); hydrogen H₂ gas 120,000,000 J/kg LHV (highest gravimetric of any chemical fuel); jet fuel Jet-A 43,150,000 J/kg per ASTM D1655. Specific energy is also the key metric for compressed-air storage (CAES), pumped-hydro per-mass equivalent (gh = 9.81·h J/kg), and projectile kinetic energy per unit mass.

It belongs to the metric measurement system.

Joules per Kilogram are commonly used in fuel comparison, battery technology, and rocket propulsion.