Energy Converter

Free Online Energy Converter

This tool supports conversion between common energy units including joule, kilojoule, megajoule, calorie, kilocalorie, kilowatt-hour, electronvolt, and BTU. Enter a value in any unit to see results in all other units in real time. All data is processed locally in your browser — nothing is uploaded to any server, fully protecting your privacy.

Features

• Supports 8 common energy unit conversions
• Covers metric, imperial, and physics units
• All units displayed simultaneously with real-time sync
• Automatic scientific notation for very large or small values
• One-click copy of conversion results
• Pure frontend offline processing, protects user privacy

Common Conversion Formulas

• 1 kJ = 1000 J
• 1 kcal = 4184 J
• 1 kWh = 3600000 J
• 1 cal = 4.184 J
• 1 BTU ≈ 1055.06 J

Common Reference Values

• 1 kilocalorie ≈ 4.184 kilojoules
• 1 kWh = 3600 kJ
• 1 BTU ≈ 1055 joules
• 1 eV ≈ 1.602×10⁻¹⁹ J

How to Use

1. 1Click on any unit card's input field
2. 2Enter a value, other units update in real time
3. 3Click the copy button to copy conversion results