Units & Numbers Tools
Energy Converter
Convert between joules, calories, kWh, BTU, and more.
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What is Energy?
An energy converter covering SI joules, food calories, electrical kWh, imperial BTUs, and physics units like eV.
How it works
Units are normalized to joules with standard definitions (1 cal = 4.184 J, 1 kWh = 3.6 MJ, etc.).
- Enter your input. Type or paste your input into the field above — the tool responds instantly.
- Review the result. Output updates live as you type. Everything runs entirely in your browser.
- Copy or download. Use the Copy button to grab the result, or Download to save it as a file.
Examples
Realistic sample
Paste or type any realistic input — the tool computes the result locally and instantly.
Common mistakes
Expecting a server round-trip
Nothing is uploaded — every tool in this category runs entirely in your browser.