Convert Joules per Kilogram-Kelvin to BTU per Pound-Rankine
Instantly convert Joules per Kilogram-Kelvin (J/(kg·K)) to BTU per Pound-Rankine (BTU/(lb·°R)) with our free online calculator.
Formula: J/(kg·K) to BTU/(lb·°R) — multiply by 2.3885e-4
Reference Table
| Joules per Kilogram-Kelvin (J/(kg·K)) | BTU per Pound-Rankine (BTU/(lb·°R)) |
|---|---|
| 1 | 0.000238846 |
| 5 | 0.00119423 |
| 10 | 0.00238846 |
| 25 | 0.00597115 |
| 50 | 0.0119423 |
| 100 | 0.0238846 |
How to Convert Joules per Kilogram-Kelvin to BTU per Pound-Rankine
Formula
To convert Joules per Kilogram-Kelvin (J/(kg·K)) to BTU per Pound-Rankine (BTU/(lb·°R)): multiply by 2.3885e-4
Step-by-Step
- Start with your value in Joules per Kilogram-Kelvin (J/(kg·K)).
- Multiply by 2.3885e-4 to perform the conversion.
- The result is your value expressed in BTU per Pound-Rankine (BTU/(lb·°R)).
Conversion Factor
1 J/(kg·K) = 0.000238846 BTU/(lb·°R)
Reverse Factor
1 BTU/(lb·°R) = 4186.8 J/(kg·K)
Worked Example
Convert 25 Joules per Kilogram-Kelvin to BTU per Pound-Rankine: 25 J/(kg·K) = 0.00597115 BTU/(lb·°R)
About Joule per Kilogram-Kelvin (J/(kg·K))
The SI unit of specific entropy (entropy per unit mass) per ISO 80000-5 §5-19.1 — used in steady-flow thermodynamics where the relevant entropy quantity is normalized to the mass flow rate through a control volume (nozzles, turbines, compressors, heat exchangers). J/(kg·K) is the universal output unit for computational thermodynamics libraries: CoolProp (open-source Helmholtz-energy-based property library), NIST REFPROP (the gold-standard reference fluid property database), IAPWS-IF97 industrial-formulation steam tables, and commercial process simulators (Aspen Plus, ChemCAD, HYSYS, ProMax). Dimensionally identical to specific heat capacity c_p in J/(kg·K), but physically distinct — entropy is a state function representing energy spreading, while c_p is a heat-flow response coefficient. Reference values per IAPWS-IF97: liquid water at 25°C has s ≈ 367 J/(kg·K); steam at 200°C and 1 bar has s ≈ 7,834 J/(kg·K); R-134a saturated vapor at 25°C has s ≈ 1,718 J/(kg·K); dry air at 25°C and 1 bar has s ≈ 6,876 J/(kg·K) (relative to reference state). Used universally in CFD strong-form energy-equation post-processing (ANSYS Fluent, OpenFOAM, STAR-CCM+).
About BTU per Pound-Rankine (BTU/(lb·°R))
An imperial specific-entropy unit equal to approximately 4,186.8 J/(kg·K) — numerically very close to (and traditionally used as numerically interchangeable with) the kJ/(kg·K) value, since BTU/(lb·°R) and kJ/(kg·K) have a conversion factor of exactly 4.1868 / 4.184 ≈ 1.0007 (a coincidence of imperial unit definitions). BTU/(lb·°R) is the dominant unit in US-edition steam tables (Keenan-Keyes-Hill, NIST/ASME Steam Tables US-customary printing), US-edition thermodynamics textbooks (Cengel-Boles, Moran-Shapiro-Boettner US editions; Borgnakke-Sonntag), ASHRAE Handbook tables (refrigerant data through 2024 edition still dual-lists), and US petroleum/refining process design per API and GPSA Engineering Data Book. Reference values: saturated liquid water at 70°F: s_f ≈ 0.0746 BTU/(lb·°R); saturated steam at 14.7 psia (1 atm boiling point): s_g ≈ 1.7567 BTU/(lb·°R); the entropy of vaporization at 1 atm s_fg ≈ 1.4446 BTU/(lb·°R). Convert BTU/(lb·°R) to kJ/(kg·K) by multiplying by 4.1868; the near-unity conversion is why dual-unit thermodynamics textbooks need only one decimal of precision to map between systems.
Quick Facts
- 1 Joule per Kilogram-Kelvin equals 0.000238846 BTU per Pound-Rankine
- 1 BTU per Pound-Rankine equals 4186.8 Joules per Kilogram-Kelvin
- Joule per Kilogram-Kelvin is a unit of specific entropy
- BTU per Pound-Rankine is a unit of specific entropy
- This conversion is commonly used in turbine design, refrigeration analysis, and power plant engineering
- The Joule per Kilogram-Kelvin belongs to the metric system
- The BTU per Pound-Rankine belongs to the imperial system
Common Joule per Kilogram-Kelvin to BTU per Pound-Rankine Conversions
| Joules per Kilogram-Kelvin (J/(kg·K)) | BTU per Pound-Rankine (BTU/(lb·°R)) |
|---|---|
| 0.01 | 0.00000238846 |
| 0.1 | 0.0000238846 |
| 0.25 | 0.0000597115 |
| 0.5 | 0.000119423 |
| 1 | 0.000238846 |
| 2 | 0.000477692 |
| 3 | 0.000716538 |
| 5 | 0.00119423 |
| 10 | 0.00238846 |
| 15 | 0.00358269 |
| 20 | 0.00477692 |
| 25 | 0.00597115 |
| 50 | 0.0119423 |
| 75 | 0.0179134 |
| 100 | 0.0238846 |
| 250 | 0.0597115 |
| 500 | 0.119423 |
| 1000 | 0.238846 |
| 5000 | 1.19423 |
| 10000 | 2.38846 |
Understanding Joules per Kilogram-Kelvin
The Joule per Kilogram-Kelvin (symbol: J/(kg·K)) is a unit of specific entropy. The SI unit of specific entropy (entropy per unit mass) per ISO 80000-5 §5-19.1 — used in steady-flow thermodynamics where the relevant entropy quantity is normalized to the mass flow rate through a control volume (nozzles, turbines, compressors, heat exchangers). J/(kg·K) is the universal output unit for computational thermodynamics libraries: CoolProp (open-source Helmholtz-energy-based property library), NIST REFPROP (the gold-standard reference fluid property database), IAPWS-IF97 industrial-formulation steam tables, and commercial process simulators (Aspen Plus, ChemCAD, HYSYS, ProMax). Dimensionally identical to specific heat capacity c_p in J/(kg·K), but physically distinct — entropy is a state function representing energy spreading, while c_p is a heat-flow response coefficient. Reference values per IAPWS-IF97: liquid water at 25°C has s ≈ 367 J/(kg·K); steam at 200°C and 1 bar has s ≈ 7,834 J/(kg·K); R-134a saturated vapor at 25°C has s ≈ 1,718 J/(kg·K); dry air at 25°C and 1 bar has s ≈ 6,876 J/(kg·K) (relative to reference state). Used universally in CFD strong-form energy-equation post-processing (ANSYS Fluent, OpenFOAM, STAR-CCM+).
It belongs to the metric measurement system.
Joules per Kilogram-Kelvin are commonly used in turbine design, refrigeration analysis, and power plant engineering.
Understanding BTU per Pound-Rankine
The BTU per Pound-Rankine (symbol: BTU/(lb·°R)) is a unit of specific entropy. An imperial specific-entropy unit equal to approximately 4,186.8 J/(kg·K) — numerically very close to (and traditionally used as numerically interchangeable with) the kJ/(kg·K) value, since BTU/(lb·°R) and kJ/(kg·K) have a conversion factor of exactly 4.1868 / 4.184 ≈ 1.0007 (a coincidence of imperial unit definitions). BTU/(lb·°R) is the dominant unit in US-edition steam tables (Keenan-Keyes-Hill, NIST/ASME Steam Tables US-customary printing), US-edition thermodynamics textbooks (Cengel-Boles, Moran-Shapiro-Boettner US editions; Borgnakke-Sonntag), ASHRAE Handbook tables (refrigerant data through 2024 edition still dual-lists), and US petroleum/refining process design per API and GPSA Engineering Data Book. Reference values: saturated liquid water at 70°F: s_f ≈ 0.0746 BTU/(lb·°R); saturated steam at 14.7 psia (1 atm boiling point): s_g ≈ 1.7567 BTU/(lb·°R); the entropy of vaporization at 1 atm s_fg ≈ 1.4446 BTU/(lb·°R). Convert BTU/(lb·°R) to kJ/(kg·K) by multiplying by 4.1868; the near-unity conversion is why dual-unit thermodynamics textbooks need only one decimal of precision to map between systems.
It belongs to the imperial measurement system.
BTU per Pound-Rankine are commonly used in turbine design, refrigeration analysis, and power plant engineering.
Why Convert Joules per Kilogram-Kelvin to BTU per Pound-Rankine?
Converting between Joules per Kilogram-Kelvin and BTU per Pound-Rankine is a frequent requirement for engineers, scientists, and students working with specific entropy 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 entropy conversion is essential.
Frequently Asked Questions
How do I convert Joules per Kilogram-Kelvin to BTU per Pound-Rankine?
The SI unit of specific entropy (entropy per unit mass) per ISO 80000-5 §5-19. To convert Joules per Kilogram-Kelvin to BTU per Pound-Rankine, multiply by 2.3885e-4. For example, 25 J/(kg·K) equals 0.00597115 BTU/(lb·°R).
How many BTU per Pound-Rankine are in 1 Joule per Kilogram-Kelvin?
There are 0.000238846 BTU per Pound-Rankine in 1 Joule per Kilogram-Kelvin.
How many Joules per Kilogram-Kelvin are in 1 BTU per Pound-Rankine?
There are 4186.8 Joules per Kilogram-Kelvin in 1 BTU per Pound-Rankine.
What is the formula for Joule per Kilogram-Kelvin to BTU per Pound-Rankine conversion?
The formula is: multiply by 2.3885e-4. This means 1 J/(kg·K) = 0.000238846 BTU/(lb·°R).
Is a Joule per Kilogram-Kelvin bigger than a BTU per Pound-Rankine?
Yes. One Joule per Kilogram-Kelvin is larger than one BTU per Pound-Rankine because 1 J/(kg·K) equals 0.000238846 BTU/(lb·°R), which is less than 1.
When do you need to convert between Joules per Kilogram-Kelvin and BTU per Pound-Rankine?
An imperial specific-entropy unit equal to approximately 4,186. Joule per Kilogram-Kelvin and BTU per Pound-Rankine are both specific entropy 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.