Convert Joules per Kilogram to BTU per Pound
Instantly convert Joules per Kilogram (J/kg) to BTU per Pound (BTU/lb) with our free online calculator.
Formula: J/kg to BTU/lb — multiply by 4.2992e-4
Reference Table
| Joules per Kilogram (J/kg) | BTU per Pound (BTU/lb) |
|---|---|
| 1 | 0.000429923 |
| 5 | 0.00214961 |
| 10 | 0.00429923 |
| 25 | 0.0107481 |
| 50 | 0.0214961 |
| 100 | 0.0429923 |
How to Convert Joules per Kilogram to BTU per Pound
Formula
To convert Joules per Kilogram (J/kg) to BTU per Pound (BTU/lb): multiply by 4.2992e-4
Step-by-Step
- Start with your value in Joules per Kilogram (J/kg).
- Multiply by 4.2992e-4 to perform the conversion.
- The result is your value expressed in BTU per Pound (BTU/lb).
Conversion Factor
1 J/kg = 0.000429923 BTU/lb
Reverse Factor
1 BTU/lb = 2326 J/kg
Worked Example
Convert 25 Joules per Kilogram to BTU per Pound: 25 J/kg = 0.0107481 BTU/lb
About Joule per Kilogram (J/kg)
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.
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 Joule per Kilogram equals 0.000429923 BTU per Pound
- 1 BTU per Pound equals 2326 Joules per Kilogram
- Joule 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 Joule per Kilogram belongs to the metric system
- The BTU per Pound belongs to the imperial system
Common Joule per Kilogram to BTU per Pound Conversions
| Joules per Kilogram (J/kg) | BTU per Pound (BTU/lb) |
|---|---|
| 0.01 | 0.00000429923 |
| 0.1 | 0.0000429923 |
| 0.25 | 0.000107481 |
| 0.5 | 0.000214961 |
| 1 | 0.000429923 |
| 2 | 0.000859845 |
| 3 | 0.00128977 |
| 5 | 0.00214961 |
| 10 | 0.00429923 |
| 15 | 0.00644884 |
| 20 | 0.00859845 |
| 25 | 0.0107481 |
| 50 | 0.0214961 |
| 75 | 0.0322442 |
| 100 | 0.0429923 |
| 250 | 0.107481 |
| 500 | 0.214961 |
| 1000 | 0.429923 |
| 5000 | 2.14961 |
| 10000 | 4.29923 |
Understanding Joules per Kilogram
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.
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 Joules per Kilogram to BTU per Pound?
Converting between Joules 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 Joules per Kilogram to BTU per Pound?
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. To convert Joules per Kilogram to BTU per Pound, multiply by 4.2992e-4. For example, 25 J/kg equals 0.0107481 BTU/lb.
How many BTU per Pound are in 1 Joule per Kilogram?
There are 0.000429923 BTU per Pound in 1 Joule per Kilogram.
How many Joules per Kilogram are in 1 BTU per Pound?
There are 2326 Joules per Kilogram in 1 BTU per Pound.
What is the formula for Joule per Kilogram to BTU per Pound conversion?
The formula is: multiply by 4.2992e-4. This means 1 J/kg = 0.000429923 BTU/lb.
Is a Joule per Kilogram bigger than a BTU per Pound?
Yes. One Joule per Kilogram is larger than one BTU per Pound because 1 J/kg equals 0.000429923 BTU/lb, which is less than 1.
When do you need to convert between Joules per Kilogram and BTU per Pound?
An imperial specific-energy unit equal to exactly 2,326 J/kg (1 BTU/lb = 1,055. Joule 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.