/convert/btus-to-kilojoules/ Convert BTU to kilojoules instantly. Includes a reference table and formula. article BTU to kilojoules Converter — 247QuickTools ,{ "@context": "https://schema.org", "@type": "SpeakableSpecification", "cssSelector": [".tool-intro", ".info-gain-section"] }
⚡ Energy

BTU to kilojoules Converter

Convert BTU to kilojoules instantly. Includes a reference table and formula.

Quick answer: To convert BTU to kilojoules, multiply by 1.05506. For example, 1 BTU = 1.05506 kilojoules. Use the calculator below for any value.
BTU to kilojoules
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Common conversions
BTU kilojoules
Formula:

How to convert BTU to kilojoules

1

Enter your value

Type the number of btu you want to convert into the left box. The result in kilojoules appears instantly in the right box. You can also type into the right box to convert in the other direction.

2

Use the swap button

Click the ⇄ Swap button to reverse the conversion — kilojoules to BTU. Your current value carries across so you don't have to re-enter anything.

3

About BTU and kilojoules

BTU and kilojoules are both energy. Use this converter to switch between them instantly.

💡 Did you know?

1 BTU = 1.055 kJ. A typical UK central heating radiator: 1,500-3,000 BTU/hour = 1.58-3.17 kJ/second. A 24 kW gas boiler = 82,000 BTU/hour. US HVAC engineers think in BTU; European engineers use kW. The 24 kW boiler = 82,000 BTU/hr conversion is the most common HVAC crossover calculation.

📊 Common conversions at a glance
BTU kilojoules
100 105.5
500 527.5
1000 1055
5000 5275
10000 1.055e+04
50000 5.275e+04
Reviewed for 2026. BTU ↔ kilojoules conversion factor verified against published reference data. Built by a UK-based qualified primary teacher and FA Level 2 coach as part of 247QuickTools' free utility-tools project.