Convert Calories per Kelvin to BTU per Rankine
Instantly convert Calories per Kelvin (cal/K) to BTU per Rankine (BTU/°R) with our free online calculator.
Formula: cal/K to BTU/°R — multiply by 0.00220314
Reference Table
| Calories per Kelvin (cal/K) | BTU per Rankine (BTU/°R) |
|---|---|
| 1 | 0.00220314 |
| 5 | 0.0110157 |
| 10 | 0.0220314 |
| 25 | 0.0550784 |
| 50 | 0.110157 |
| 100 | 0.220314 |
How to Convert Calories per Kelvin to BTU per Rankine
Formula
To convert Calories per Kelvin (cal/K) to BTU per Rankine (BTU/°R): multiply by 0.00220314
Step-by-Step
- Start with your value in Calories per Kelvin (cal/K).
- Multiply by 0.00220314 to perform the conversion.
- The result is your value expressed in BTU per Rankine (BTU/°R).
Conversion Factor
1 cal/K = 0.00220314 BTU/°R
Reverse Factor
1 BTU/°R = 453.898 cal/K
Worked Example
Convert 25 Calories per Kelvin to BTU per Rankine: 25 cal/K = 0.0550784 BTU/°R
About Calorie per Kelvin (cal/K)
A CGS entropy unit equal to exactly 4.184 J/K (using the thermochemical calorie definition per NIST SP 811). cal/K is a legacy unit that persists in older chemistry and biochemistry literature, with the equivalent molar form cal/(K·mol) (often abbreviated 'e.u.' for 'entropy unit' in older textbooks) appearing routinely in: classical physical-chemistry references pre-1980 (Lewis-Randall, Pitzer-Brewer thermodynamics texts), biochemistry literature on protein-folding entropy (typical ΔS_folding ranges from -50 to +50 cal/(K·mol) per residue), enzymology free-energy diagrams (Eyring-transition-state analysis), and pharmaceutical drug-binding thermodynamics (isothermal titration calorimetry / ITC papers in J. Mol. Biol., Biochemistry, Protein Sci. through the 1990s). The bond-dissociation entropy of H₂(g) → 2H(g) at 298 K is ΔS° = +24.4 cal/(K·mol). Modern publications increasingly use SI J/K, but cal/K appears in cross-references to older databases (NIST WebBook still dual-lists), in NMR-relaxation thermodynamic-cycle interpretation, and in physical-organic-chemistry literature where Arrhenius pre-exponential factors are quoted with entropy in cal-units.
About BTU per Rankine (BTU/°R)
An imperial entropy unit equal to approximately 1,899.11 J/K (1 BTU = 1,055.06 J, 1 °R = 5/9 K, ratio = 1,899.11). BTU/°R is the working unit of US-edition steam-table absolute entropy values (Keenan-Keyes-Hill steam tables, NIST/ASME Steam Tables published in BTU units), US refrigeration-cycle design per ASHRAE Handbook chapters 1-2 (Fundamentals + Refrigeration tables), and US-edition gas-cycle thermodynamics textbooks (Cengel-Boles, Moran-Shapiro both still publish dual-unit editions). Standard reference values: saturated liquid water at 70°F has absolute specific entropy s_f ≈ 0.0746 BTU/(lb·°R); saturated steam at 212°F (1 atm) has s_g ≈ 1.7567 BTU/(lb·°R) — the entropy gain of vaporization. Total entropy flows in US power-plant heat balances are sometimes reported in BTU/(°R·hr) or BTU/(°R·s). For a large industrial process like a 600 MW(e) coal-fired Rankine cycle, total entropy rejection rate ≈ 5 × 10⁶ BTU/(°R·hr). Convert BTU/°R to J/K by multiplying by 1899.11; to kJ/K by multiplying by 1.899.
Quick Facts
- 1 Calorie per Kelvin equals 0.00220314 BTU per Rankine
- 1 BTU per Rankine equals 453.898 Calories per Kelvin
- Calorie per Kelvin is a unit of entropy
- BTU per Rankine is a unit of entropy
- This conversion is commonly used in thermodynamics, refrigeration cycles, and chemical engineering
- The Calorie per Kelvin belongs to the metric system
- The BTU per Rankine belongs to the imperial system
Common Calorie per Kelvin to BTU per Rankine Conversions
| Calories per Kelvin (cal/K) | BTU per Rankine (BTU/°R) |
|---|---|
| 0.01 | 0.0000220314 |
| 0.1 | 0.000220314 |
| 0.25 | 0.000550784 |
| 0.5 | 0.00110157 |
| 1 | 0.00220314 |
| 2 | 0.00440627 |
| 3 | 0.00660941 |
| 5 | 0.0110157 |
| 10 | 0.0220314 |
| 15 | 0.0330471 |
| 20 | 0.0440627 |
| 25 | 0.0550784 |
| 50 | 0.110157 |
| 75 | 0.165235 |
| 100 | 0.220314 |
| 250 | 0.550784 |
| 500 | 1.10157 |
| 1000 | 2.20314 |
| 5000 | 11.0157 |
| 10000 | 22.0314 |
Understanding Calories per Kelvin
The Calorie per Kelvin (symbol: cal/K) is a unit of entropy. A CGS entropy unit equal to exactly 4.184 J/K (using the thermochemical calorie definition per NIST SP 811). cal/K is a legacy unit that persists in older chemistry and biochemistry literature, with the equivalent molar form cal/(K·mol) (often abbreviated 'e.u.' for 'entropy unit' in older textbooks) appearing routinely in: classical physical-chemistry references pre-1980 (Lewis-Randall, Pitzer-Brewer thermodynamics texts), biochemistry literature on protein-folding entropy (typical ΔS_folding ranges from -50 to +50 cal/(K·mol) per residue), enzymology free-energy diagrams (Eyring-transition-state analysis), and pharmaceutical drug-binding thermodynamics (isothermal titration calorimetry / ITC papers in J. Mol. Biol., Biochemistry, Protein Sci. through the 1990s). The bond-dissociation entropy of H₂(g) → 2H(g) at 298 K is ΔS° = +24.4 cal/(K·mol). Modern publications increasingly use SI J/K, but cal/K appears in cross-references to older databases (NIST WebBook still dual-lists), in NMR-relaxation thermodynamic-cycle interpretation, and in physical-organic-chemistry literature where Arrhenius pre-exponential factors are quoted with entropy in cal-units.
It belongs to the metric measurement system.
Calories per Kelvin are commonly used in thermodynamics, refrigeration cycles, and chemical engineering.
Understanding BTU per Rankine
The BTU per Rankine (symbol: BTU/°R) is a unit of entropy. An imperial entropy unit equal to approximately 1,899.11 J/K (1 BTU = 1,055.06 J, 1 °R = 5/9 K, ratio = 1,899.11). BTU/°R is the working unit of US-edition steam-table absolute entropy values (Keenan-Keyes-Hill steam tables, NIST/ASME Steam Tables published in BTU units), US refrigeration-cycle design per ASHRAE Handbook chapters 1-2 (Fundamentals + Refrigeration tables), and US-edition gas-cycle thermodynamics textbooks (Cengel-Boles, Moran-Shapiro both still publish dual-unit editions). Standard reference values: saturated liquid water at 70°F has absolute specific entropy s_f ≈ 0.0746 BTU/(lb·°R); saturated steam at 212°F (1 atm) has s_g ≈ 1.7567 BTU/(lb·°R) — the entropy gain of vaporization. Total entropy flows in US power-plant heat balances are sometimes reported in BTU/(°R·hr) or BTU/(°R·s). For a large industrial process like a 600 MW(e) coal-fired Rankine cycle, total entropy rejection rate ≈ 5 × 10⁶ BTU/(°R·hr). Convert BTU/°R to J/K by multiplying by 1899.11; to kJ/K by multiplying by 1.899.
It belongs to the imperial measurement system.
BTU per Rankine are commonly used in thermodynamics, refrigeration cycles, and chemical engineering.
Why Convert Calories per Kelvin to BTU per Rankine?
Converting between Calories per Kelvin and BTU per Rankine is a frequent requirement for engineers, scientists, and students working with 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 entropy conversion is essential.
Frequently Asked Questions
How do I convert Calories per Kelvin to BTU per Rankine?
A CGS entropy unit equal to exactly 4. To convert Calories per Kelvin to BTU per Rankine, multiply by 0.00220314. For example, 25 cal/K equals 0.0550784 BTU/°R.
How many BTU per Rankine are in 1 Calorie per Kelvin?
There are 0.00220314 BTU per Rankine in 1 Calorie per Kelvin.
How many Calories per Kelvin are in 1 BTU per Rankine?
There are 453.898 Calories per Kelvin in 1 BTU per Rankine.
What is the formula for Calorie per Kelvin to BTU per Rankine conversion?
The formula is: multiply by 0.00220314. This means 1 cal/K = 0.00220314 BTU/°R.
Is a Calorie per Kelvin bigger than a BTU per Rankine?
Yes. One Calorie per Kelvin is larger than one BTU per Rankine because 1 cal/K equals 0.00220314 BTU/°R, which is less than 1.
When do you need to convert between Calories per Kelvin and BTU per Rankine?
An imperial entropy unit equal to approximately 1,899. Calorie per Kelvin and BTU per Rankine are both 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.