Convert Kilojoules per Kilogram to BTU per Pound
Instantly convert Kilojoules per Kilogram (kJ/kg) to BTU per Pound (BTU/lb) with our free online calculator.
Formula: kJ/kg to BTU/lb — multiply by 0.429923
Reference Table
| Kilojoules per Kilogram (kJ/kg) | BTU per Pound (BTU/lb) |
|---|---|
| 1 | 0.429923 |
| 5 | 2.14961 |
| 10 | 4.29923 |
| 25 | 10.7481 |
| 50 | 21.4961 |
| 100 | 42.9923 |
How to Convert Kilojoules per Kilogram to BTU per Pound
Formula
To convert Kilojoules per Kilogram (kJ/kg) to BTU per Pound (BTU/lb): multiply by 0.429923
Step-by-Step
- Start with your value in Kilojoules per Kilogram (kJ/kg).
- Multiply by 0.429923 to perform the conversion.
- The result is your value expressed in BTU per Pound (BTU/lb).
Conversion Factor
1 kJ/kg = 0.429923 BTU/lb
Reverse Factor
1 BTU/lb = 2.326 kJ/kg
Worked Example
Convert 25 Kilojoules per Kilogram to BTU per Pound: 25 kJ/kg = 10.7481 BTU/lb
About Kilojoule per Kilogram (kJ/kg)
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.
About BTU per Pound (BTU/lb)
An imperial specific-energy unit equal to exactly 2,326 J/kg (1 BTU/lb = 1,055.06 J / 0.45359237 kg = 2,326.000 J/kg). BTU/lb is dominant on US steam tables, HVAC enthalpy/psychrometric calculations per ASHRAE Handbook Fundamentals chapter 1, heating-fuel and refining specific-energy reporting per API MPMS and GPSA Engineering Data Book, and natural-gas heating-value certification. Reference values: natural gas heating value (residential pipeline grade) ~22,000 BTU/lb HHV (higher heating value with water-vapor condensation credit); LNG 21,500 BTU/lb; #2 fuel oil ~19,500 BTU/lb; gasoline 19,500-20,000 BTU/lb LHV; coal anthracite 13,000-15,000 BTU/lb; bituminous 10,500-14,000 BTU/lb per ASTM D388 classification; sub-bituminous 8,500-13,000 BTU/lb; lignite 4,000-8,300 BTU/lb. Saturated liquid water at 70°F: h_f ≈ 38.1 BTU/lb; saturated steam at 14.7 psia: h_g ≈ 1,150.5 BTU/lb. Refrigerant enthalpy/entropy tables in US-edition ASHRAE Handbook and US-customary printings of Mollier h-s diagrams use BTU/lb throughout. Convert BTU/lb to kJ/kg by multiplying by 2.326.
Quick Facts
- 1 Kilojoule per Kilogram equals 0.429923 BTU per Pound
- 1 BTU per Pound equals 2.326 Kilojoules per Kilogram
- Kilojoule per Kilogram is a unit of specific energy
- BTU per Pound is a unit of specific energy
- This conversion is commonly used in fuel comparison, battery technology, and rocket propulsion
- The Kilojoule per Kilogram belongs to the metric system
- The BTU per Pound belongs to the imperial system
Common Kilojoule per Kilogram to BTU per Pound Conversions
| Kilojoules per Kilogram (kJ/kg) | BTU per Pound (BTU/lb) |
|---|---|
| 0.01 | 0.00429923 |
| 0.1 | 0.0429923 |
| 0.25 | 0.107481 |
| 0.5 | 0.214961 |
| 1 | 0.429923 |
| 2 | 0.859845 |
| 3 | 1.28977 |
| 5 | 2.14961 |
| 10 | 4.29923 |
| 15 | 6.44884 |
| 20 | 8.59845 |
| 25 | 10.7481 |
| 50 | 21.4961 |
| 75 | 32.2442 |
| 100 | 42.9923 |
| 250 | 107.481 |
| 500 | 214.961 |
| 1000 | 429.923 |
| 5000 | 2149.61 |
| 10000 | 4299.23 |
Understanding Kilojoules 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.
Understanding BTU per Pound
The BTU per Pound (symbol: BTU/lb) is a unit of specific energy. An imperial specific-energy unit equal to exactly 2,326 J/kg (1 BTU/lb = 1,055.06 J / 0.45359237 kg = 2,326.000 J/kg). BTU/lb is dominant on US steam tables, HVAC enthalpy/psychrometric calculations per ASHRAE Handbook Fundamentals chapter 1, heating-fuel and refining specific-energy reporting per API MPMS and GPSA Engineering Data Book, and natural-gas heating-value certification. Reference values: natural gas heating value (residential pipeline grade) ~22,000 BTU/lb HHV (higher heating value with water-vapor condensation credit); LNG 21,500 BTU/lb; #2 fuel oil ~19,500 BTU/lb; gasoline 19,500-20,000 BTU/lb LHV; coal anthracite 13,000-15,000 BTU/lb; bituminous 10,500-14,000 BTU/lb per ASTM D388 classification; sub-bituminous 8,500-13,000 BTU/lb; lignite 4,000-8,300 BTU/lb. Saturated liquid water at 70°F: h_f ≈ 38.1 BTU/lb; saturated steam at 14.7 psia: h_g ≈ 1,150.5 BTU/lb. Refrigerant enthalpy/entropy tables in US-edition ASHRAE Handbook and US-customary printings of Mollier h-s diagrams use BTU/lb throughout. Convert BTU/lb to kJ/kg by multiplying by 2.326.
It belongs to the imperial measurement system.
BTU per Pound are commonly used in fuel comparison, battery technology, and rocket propulsion.
Why Convert Kilojoules per Kilogram to BTU per Pound?
Converting between Kilojoules per Kilogram and BTU per Pound is a frequent requirement for engineers, scientists, and students working with specific energy values. Different industries and regions favour different unit systems, so having a dependable conversion tool saves time and prevents errors in technical calculations. Whether you are verifying a specification sheet, cross-checking simulation results, or preparing a report for an international audience, accurate specific energy conversion is essential.
Frequently Asked Questions
How do I convert Kilojoules per Kilogram to BTU per Pound?
A metric specific-energy unit equal to exactly 1,000 J/kg. To convert Kilojoules per Kilogram to BTU per Pound, multiply by 0.429923. For example, 25 kJ/kg equals 10.7481 BTU/lb.
How many BTU per Pound are in 1 Kilojoule per Kilogram?
There are 0.429923 BTU per Pound in 1 Kilojoule per Kilogram.
How many Kilojoules per Kilogram are in 1 BTU per Pound?
There are 2.326 Kilojoules per Kilogram in 1 BTU per Pound.
What is the formula for Kilojoule per Kilogram to BTU per Pound conversion?
The formula is: multiply by 0.429923. This means 1 kJ/kg = 0.429923 BTU/lb.
Is a Kilojoule per Kilogram bigger than a BTU per Pound?
Yes. One Kilojoule per Kilogram is larger than one BTU per Pound because 1 kJ/kg equals 0.429923 BTU/lb, which is less than 1.
When do you need to convert between Kilojoules per Kilogram and BTU per Pound?
An imperial specific-energy unit equal to exactly 2,326 J/kg (1 BTU/lb = 1,055. Kilojoule per Kilogram and BTU per Pound are both specific energy units, so conversion comes up whenever one source of information uses one unit and another uses the other — a classic cross-reference challenge in engineering, trade, travel, and everyday life.