How do I convert joules to calories?

Divide the energy in joules by 4.184. This converter uses the thermochemical calorie, defined as exactly 1 cal = 4.184 J. For example, 4.184 J = 1 cal.

Is this converter accurate?

Yes, for the thermochemical calorie (1 cal = 4.184 J exactly). Note that the 'large' food Calorie (kcal) is 1000 of these calories, and the international-table calorie (4.1868 J) differs slightly — this tool uses the thermochemical definition.

Is my data sent anywhere?

No. The converter is privacy-first — all processing happens locally in your browser and nothing you type leaves your device.

Joules to Calories Converter

This free energy converter changes joules (J) into calories (cal) and back again, using the thermochemical calorie defined as exactly 1 cal = 4.184 J. So 4.184 J equals 1 cal, and 1000 J is about 239 cal.

Type a value in either field — the result updates in real time. The reference table below shows common conversions at a glance. Note that the dietary “Calorie” (kcal) equals 1000 of these calories. All calculations run entirely in your browser with no data sent to any server.