Convert BTU per Pound-Fahrenheit to Kilojoules per Kilogram-Kelvin
Instantly convert BTU per Pound-Fahrenheit (BTU/(lb·°F)) to Kilojoules per Kilogram-Kelvin (kJ/(kg·K)) with our free online calculator.
Formula: BTU/(lb·°F) to kJ/(kg·K) — multiply by 4.1868
Reference Table
| BTU per Pound-Fahrenheit (BTU/(lb·°F)) | Kilojoules per Kilogram-Kelvin (kJ/(kg·K)) |
|---|---|
| 1 | 4.1868 |
| 5 | 20.934 |
| 10 | 41.868 |
| 25 | 104.67 |
| 50 | 209.34 |
| 100 | 418.68 |
How to Convert BTU per Pound-Fahrenheit to Kilojoules per Kilogram-Kelvin
Formula
To convert BTU per Pound-Fahrenheit (BTU/(lb·°F)) to Kilojoules per Kilogram-Kelvin (kJ/(kg·K)): multiply by 4.1868
Step-by-Step
- Start with your value in BTU per Pound-Fahrenheit (BTU/(lb·°F)).
- Multiply by 4.1868 to perform the conversion.
- The result is your value expressed in Kilojoules per Kilogram-Kelvin (kJ/(kg·K)).
Conversion Factor
1 BTU/(lb·°F) = 4.1868 kJ/(kg·K)
Reverse Factor
1 kJ/(kg·K) = 0.238846 BTU/(lb·°F)
Worked Example
Convert 25 BTU per Pound-Fahrenheit to Kilojoules per Kilogram-Kelvin: 25 BTU/(lb·°F) = 104.67 kJ/(kg·K)
About BTU per Pound-Fahrenheit (BTU/(lb·°F))
An imperial specific-heat unit (≈ 4,186.8 J/(kg·K)) widely used in US HVAC, petroleum engineering, thermodynamics, and process-engineering work. By the BTU's definition (1 BTU = heat to raise 1 lb of water by 1 °F at 60 °F), water has a specific heat of exactly 1.000 BTU/(lb·°F) — numerically identical to water's value in cal/(g·°C) since both unit systems calibrate to the same physical material. US steam tables (Keenan, Keyes, Hill, Moore; Power's Steam Tables), ASHRAE Handbook fundamentals chapters on humidification + air-property calculations, petroleum-reservoir thermal-recovery simulators (CMG STARS, Computer Modelling Group), and Perry's Chemical Engineers' Handbook all default to BTU/(lb·°F) for cp / cv values. Reference values: ideal air cp = 0.240 BTU/(lb·°F), cv = 0.171 BTU/(lb·°F); structural steel 0.107 BTU/(lb·°F); aluminum 0.214 BTU/(lb·°F); typical engineering polymer 0.3-0.5 BTU/(lb·°F). Convert BTU/(lb·°F) to J/(kg·K) by multiplying by 4,186.8; to kJ/(kg·K) by multiplying by 4.187.
About Kilojoule per Kilogram-Kelvin (kJ/(kg·K))
A metric specific-heat unit equal to exactly 1,000 J/(kg·K). Because most common substances have specific heats in the 0.3-5 kJ/(kg·K) range, kJ/(kg·K) is the default working unit on every published thermodynamic property table (IAPWS-IF97 steam tables, NIST REFPROP refrigerant data, NASA CEA gas-property tables, Çengel-Boles 'Thermodynamics: An Engineering Approach' textbook, Moran-Shapiro 'Fundamentals of Engineering Thermodynamics'). Reference values: water at 25 °C is 4.186 kJ/(kg·K); structural steel ~0.49 kJ/(kg·K); aluminum 0.897 kJ/(kg·K); liquid nitrogen at saturation ~1.04 kJ/(kg·K); R-134a refrigerant vapour ~1.0 kJ/(kg·K) at saturation; R-1234yf (low-GWP automotive refrigerant) ~0.95 kJ/(kg·K). For ideal-gas calculations: dry air cp = 1.005 kJ/(kg·K), cv = 0.718 kJ/(kg·K), with ratio γ = cp/cv = 1.4 used in compressible-flow analysis. Steam tables in Çengel-Boles default to kJ/(kg·K) for both cp and cv.
Quick Facts
- 1 BTU per Pound-Fahrenheit equals 4.1868 Kilojoules per Kilogram-Kelvin
- 1 Kilojoule per Kilogram-Kelvin equals 0.238846 BTU per Pound-Fahrenheit
- BTU per Pound-Fahrenheit is a unit of specific heat capacity
- Kilojoule per Kilogram-Kelvin is a unit of specific heat capacity
- This conversion is commonly used in thermal design, material selection, and climate modelling
- The BTU per Pound-Fahrenheit belongs to the imperial system
- The Kilojoule per Kilogram-Kelvin belongs to the metric system
Common BTU per Pound-Fahrenheit to Kilojoule per Kilogram-Kelvin Conversions
| BTU per Pound-Fahrenheit (BTU/(lb·°F)) | Kilojoules per Kilogram-Kelvin (kJ/(kg·K)) |
|---|---|
| 0.01 | 0.041868 |
| 0.1 | 0.41868 |
| 0.25 | 1.0467 |
| 0.5 | 2.0934 |
| 1 | 4.1868 |
| 2 | 8.3736 |
| 3 | 12.5604 |
| 5 | 20.934 |
| 10 | 41.868 |
| 15 | 62.802 |
| 20 | 83.736 |
| 25 | 104.67 |
| 50 | 209.34 |
| 75 | 314.01 |
| 100 | 418.68 |
| 250 | 1046.7 |
| 500 | 2093.4 |
| 1000 | 4186.8 |
| 5000 | 20934 |
| 10000 | 41868 |
Understanding BTU per Pound-Fahrenheit
The BTU per Pound-Fahrenheit (symbol: BTU/(lb·°F)) is a unit of specific heat capacity. An imperial specific-heat unit (≈ 4,186.8 J/(kg·K)) widely used in US HVAC, petroleum engineering, thermodynamics, and process-engineering work. By the BTU's definition (1 BTU = heat to raise 1 lb of water by 1 °F at 60 °F), water has a specific heat of exactly 1.000 BTU/(lb·°F) — numerically identical to water's value in cal/(g·°C) since both unit systems calibrate to the same physical material. US steam tables (Keenan, Keyes, Hill, Moore; Power's Steam Tables), ASHRAE Handbook fundamentals chapters on humidification + air-property calculations, petroleum-reservoir thermal-recovery simulators (CMG STARS, Computer Modelling Group), and Perry's Chemical Engineers' Handbook all default to BTU/(lb·°F) for cp / cv values. Reference values: ideal air cp = 0.240 BTU/(lb·°F), cv = 0.171 BTU/(lb·°F); structural steel 0.107 BTU/(lb·°F); aluminum 0.214 BTU/(lb·°F); typical engineering polymer 0.3-0.5 BTU/(lb·°F). Convert BTU/(lb·°F) to J/(kg·K) by multiplying by 4,186.8; to kJ/(kg·K) by multiplying by 4.187.
It belongs to the imperial measurement system.
BTU per Pound-Fahrenheit are commonly used in thermal design, material selection, and climate modelling.
Understanding Kilojoules per Kilogram-Kelvin
The Kilojoule per Kilogram-Kelvin (symbol: kJ/(kg·K)) is a unit of specific heat capacity. A metric specific-heat unit equal to exactly 1,000 J/(kg·K). Because most common substances have specific heats in the 0.3-5 kJ/(kg·K) range, kJ/(kg·K) is the default working unit on every published thermodynamic property table (IAPWS-IF97 steam tables, NIST REFPROP refrigerant data, NASA CEA gas-property tables, Çengel-Boles 'Thermodynamics: An Engineering Approach' textbook, Moran-Shapiro 'Fundamentals of Engineering Thermodynamics'). Reference values: water at 25 °C is 4.186 kJ/(kg·K); structural steel ~0.49 kJ/(kg·K); aluminum 0.897 kJ/(kg·K); liquid nitrogen at saturation ~1.04 kJ/(kg·K); R-134a refrigerant vapour ~1.0 kJ/(kg·K) at saturation; R-1234yf (low-GWP automotive refrigerant) ~0.95 kJ/(kg·K). For ideal-gas calculations: dry air cp = 1.005 kJ/(kg·K), cv = 0.718 kJ/(kg·K), with ratio γ = cp/cv = 1.4 used in compressible-flow analysis. Steam tables in Çengel-Boles default to kJ/(kg·K) for both cp and cv.
It belongs to the metric measurement system.
Kilojoules per Kilogram-Kelvin are commonly used in thermal design, material selection, and climate modelling.
Why Convert BTU per Pound-Fahrenheit to Kilojoules per Kilogram-Kelvin?
Converting between BTU per Pound-Fahrenheit and Kilojoules per Kilogram-Kelvin is a frequent requirement for engineers, scientists, and students working with specific heat capacity 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 heat capacity conversion is essential.
Frequently Asked Questions
How do I convert BTU per Pound-Fahrenheit to Kilojoules per Kilogram-Kelvin?
An imperial specific-heat unit (≈ 4,186. To convert BTU per Pound-Fahrenheit to Kilojoules per Kilogram-Kelvin, multiply by 4.1868. For example, 25 BTU/(lb·°F) equals 104.67 kJ/(kg·K).
How many Kilojoules per Kilogram-Kelvin are in 1 BTU per Pound-Fahrenheit?
There are 4.1868 Kilojoules per Kilogram-Kelvin in 1 BTU per Pound-Fahrenheit.
How many BTU per Pound-Fahrenheit are in 1 Kilojoule per Kilogram-Kelvin?
There are 0.238846 BTU per Pound-Fahrenheit in 1 Kilojoule per Kilogram-Kelvin.
What is the formula for BTU per Pound-Fahrenheit to Kilojoule per Kilogram-Kelvin conversion?
The formula is: multiply by 4.1868. This means 1 BTU/(lb·°F) = 4.1868 kJ/(kg·K).
Is a BTU per Pound-Fahrenheit bigger than a Kilojoule per Kilogram-Kelvin?
No. One BTU per Pound-Fahrenheit is smaller than one Kilojoule per Kilogram-Kelvin because 1 BTU/(lb·°F) equals 4.1868 kJ/(kg·K), which is greater than 1.
When do you need to convert between BTU per Pound-Fahrenheit and Kilojoules per Kilogram-Kelvin?
A metric specific-heat unit equal to exactly 1,000 J/(kg·K). BTU per Pound-Fahrenheit and Kilojoule per Kilogram-Kelvin are both specific heat 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.