Btu to Kilojoule Converter
Enter the value that you want to convert Btu (Btu) to kilojoule (kJ) or kilojoule to Btu.Also written as BTU to KJ conversion.
1 Btu = 1.0550559 kilojoule
Formula: kilojoule = Btu value × 1.0550559
BTU to KJ — Btu to kilojoule
10 Btu = 10.55056 kilojoule
Popular Energy Converters:
Btu vs Kilojoule
About the Btu
Btu (Btu) is a unit of energy measurement. 1 Btu is equal to 1.0550559 kilojoule.
About the Kilojoule
Kilojoule (kJ) is a unit of energy measurement. 1 kilojoule is equal to 0.9478171 Btu.
Energy Units in Different Fields
Energy measurement units reflect their historical origins across different industries. Electrical engineers use kilowatt-hours, nutritionists use calories, physicists use joules, heating engineers use BTUs, and the petroleum industry uses barrels of oil equivalent. Converting between these units is essential for energy auditing, comparing fuel sources, sizing HVAC systems, and understanding electricity bills relative to gas consumption.
Btu to kilojoule metric conversion table
| 0.01 Btu | = | 0.01055 kJ |
| 0.1 Btu | = | 0.10551 kJ |
| 1 Btu | = | 1.05506 kJ |
| 2 Btu | = | 2.11011 kJ |
| 3 Btu | = | 3.16517 kJ |
| 4 Btu | = | 4.22022 kJ |
| 5 Btu | = | 5.27528 kJ |
| 6 Btu | = | 6.33034 kJ |
| 7 Btu | = | 7.38539 kJ |
| 8 Btu | = | 8.44045 kJ |
| 9 Btu | = | 9.49550 kJ |
| 10 Btu | = | 10.55056 kJ |
| 11 Btu | = | 11.60561 kJ |
| 12 Btu | = | 12.66067 kJ |
| 13 Btu | = | 13.71573 kJ |
| 14 Btu | = | 14.77078 kJ |
| 15 Btu | = | 15.82584 kJ |
| 16 Btu | = | 16.88089 kJ |
| 17 Btu | = | 17.93595 kJ |
| 18 Btu | = | 18.99101 kJ |
| 19 Btu | = | 20.04606 kJ |
| 20 Btu | = | 21.10112 kJ |
| 30 Btu | = | 31.65168 kJ |
| 40 Btu | = | 42.20223 kJ |
| 50 Btu | = | 52.75279 kJ |
| 60 Btu | = | 63.30335 kJ |
| 70 Btu | = | 73.85391 kJ |
| 80 Btu | = | 84.40447 kJ |
| 90 Btu | = | 94.95503 kJ |
| 100 Btu | = | 105.50559 kJ |
| 200 Btu | = | 211.01117 kJ |
| 300 Btu | = | 316.51676 kJ |
| 400 Btu | = | 422.02234 kJ |
| 500 Btu | = | 527.52793 kJ |
| 600 Btu | = | 633.03351 kJ |
| 700 Btu | = | 738.53910 kJ |
| 800 Btu | = | 844.04468 kJ |
| 900 Btu | = | 949.55027 kJ |
| 1000 Btu | = | 1055.05585 kJ |
How to Convert BTU to KJ (Btu to Kilojoule)?
We can convert Btu to kilojoule by using an example.
Example:
Convert 20 Btu to Kilojoule?
We know 1 Btu = 1.0550559 kilojoule; 1 Kilojoule = 0.9478171 Btu.
20 Btu = ___kJ
20 × 1.0550559 = 21.10112 kJ (we know 1 Btu = 1.0550559 kilojoule)
Answer:
20 Btu = 21.10112 kilojoule
How to Convert BTU to Kilojoules (Step-by-Step)
Converting BTU to kJ is common when translating US heating specifications to metric standards. The conversion factor is 1 BTU = 1.05506 kJ. This is the same as dividing the joule conversion by 1000.
- Identify the BTU value from the equipment rating or energy measurement.
- Multiply the BTU value by 1.05506 to get kilojoules.
- For furnace hourly ratings, the result gives kJ/hr energy output.
- Round based on the precision of your original BTU measurement.
Common BTU to kJ Conversions
Practical references for US heating equipment ratings converted to metric kilojoules.
| Btu | Kilojoule |
|---|---|
| 1 BTU | 1.055 kJ |
| 100 BTU | 105.5 kJ |
| 1,000 BTU | 1,055 kJ |
| 3,412 BTU | 3,600 kJ |
| 12,000 BTU | 12,661 kJ |
| 40,000 BTU | 42,202 kJ |
| 100,000 BTU | 105,506 kJ |
Solved Examples: BTU to kJ
Question 1: A gas grill burner is rated at 25,000 BTU. Convert to kJ.
Solution:
Start with 25,000 BTU.
Multiply by 1.05506: 25,000 × 1.05506 = 26,376.5 kJ.
Answer: 25,000 BTU = 26,376.5 kJ ≈ 26.4 MJ
Question 2: A portable propane heater outputs 9,000 BTU/hr. Express in kJ/hr.
Solution:
Start with 9,000 BTU/hr.
Multiply by 1.05506: 9,000 × 1.05506 = 9,495.5 kJ/hr.
Answer: 9,000 BTU/hr = 9,495.5 kJ/hr
Question 3: Natural gas has an energy content of about 1,030 BTU per cubic foot. Convert to kJ.
Solution:
Start with 1,030 BTU/ft³.
Multiply by 1.05506: 1,030 × 1.05506 = 1,086.7 kJ/ft³.
Answer: 1,030 BTU/ft³ = 1,086.7 kJ/ft³
Question 4: A residential furnace is rated at 60,000 BTU/hr input. Convert to kJ/hr.
Solution:
Start with 60,000 BTU/hr.
Multiply by 1.05506: 60,000 × 1.05506 = 63,303.6 kJ/hr.
This can also be expressed as 63.3 MJ/hr or about 17.6 kW.
Answer: 60,000 BTU/hr = 63,303.6 kJ/hr ≈ 63.3 MJ/hr
Practice: BTU to kJ
Try solving these on your own to test your understanding:
- Convert 500 BTU to kJ. (Answer: 527.5 kJ)
- A tank water heater recovery is 40,000 BTU/hr. Convert to kJ. (Answer: 42,202 kJ)
- Convert 75,000 BTU to kJ and MJ. (Answer: 79,130 kJ = 79.13 MJ)
- A gas dryer uses 22,000 BTU/hr. Express in kJ. (Answer: 23,211 kJ)
- Convert 150 BTU to kJ. (Answer: 158.3 kJ)
Gas Appliance Specifications: BTU vs kJ
In the US, all gas appliances (furnaces, water heaters, stoves, dryers) list their input and output ratings in BTU/hr. Canadian equipment often shows both BTU/hr and kW. A typical gas range burner runs 5,000–15,000 BTU/hr (5,275–15,826 kJ/hr), while a high-performance commercial burner can exceed 25,000 BTU/hr (26,377 kJ/hr). When comparing appliance efficiency between US and European models, converting to a common unit (kJ or kW) is essential.
Energy Content of Fuels in BTU and kJ
Common fuel energy values: Natural gas ≈ 1,030 BTU/ft³ (1,087 kJ/ft³) or 37.3 MJ/m³. Propane ≈ 91,500 BTU/gallon (96,540 kJ/gal). Heating oil ≈ 138,500 BTU/gallon (146,140 kJ/gal). These values are essential for calculating heating costs and comparing fuel economies between countries using different measurement systems.
Key Takeaways
- Multiply BTU by 1.05506 to get kilojoules.
- BTU and kJ are nearly 1:1 (kJ is just ~5.5% larger).
- 1 therm (100,000 BTU) = 105,506 kJ ≈ 105.5 MJ.
- 3,412 BTU = 3,600 kJ = 1 kWh — a key equivalence for electricity comparisons.
- Gas appliances in the US use BTU/hr; metric countries use kW (= kJ/s).
- For quick estimates, BTU ≈ kJ (just add ~5% to the BTU number).
Btu to Kilojoule Conversion Formula
kilojoule = Btu × 1.0550559
1 Btu = 1.0550559 kilojoule
1 kilojoule = 0.9478171 Btu
Reverse: Btu = kilojoule × 0.9478171
Frequently Asked Questions
How many kilojoule are in 1 Btu?
There are 1.0550559 kilojoule in 1 Btu. To convert Btu to kilojoule, multiply the value by 1.0550559.
How do I convert Btu to kilojoule?
Multiply your Btu value by 1.0550559 to get the equivalent in kilojoule. For example, 5 Btu = 5 × 1.0550559 = 5.27528 kilojoule.
How do I convert kilojoule to Btu?
Multiply your kilojoule value by 0.9478171 to get the equivalent in Btu. Alternatively, divide by 1.0550559.
What is 10 Btu in kilojoule?
10 Btu is equal to 10.55056 kilojoule.
What is 100 Btu in kilojoule?
100 Btu is equal to 105.50559 kilojoule.