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Energy Converter

Convert energy units instantly. Shift between Joules (J), Calories (cal), Kilowatt-hours (kWh), and BTUs with precision. Fast, free, and private.

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About Energy Converter

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Zero Server UploadsExecution occurs entirely in browser memory via WebAssembly and HTML5 Canvas.

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Insert Value

Type the energy figure into any unit input box.

Instant Update

The entire grid will refresh with equivalent measurements.

Consult Data

Get accurate, high-decimal results for scientific or home efficiency use.

Our professional Energy Converter helps you navigate the complex world of energy units. From measuring the work of a physics problem in Joules to calculating household electricity in kWh or dietary energy in Calories, this tool provides instant, accurate transformations 100% on your device.

Key Features

Electrical Energy

Full conversion for kWh and Watt-seconds.

Thermal & Sl

Support for Calories, BTUs, and Joules.

Physics-Ready

Convert to Electronvolts (eV) for high-end scientific work.

Frequently Asked Questions

1 kWh is equal to exactly 3,600,000 Joules (or 3.6 Megajoules).

1 Joule (J) is approximately 0.239006 thermochemical calories (cal).

1 British Thermal Unit (BTU) is approximately 1,055.06 Joules.

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Last updated on March 22, 2026