Joules to Calories Converter

Convert scientific energy units correctly

Joules are the SI energy unit, while the small thermochemical calorie still appears in chemistry and heat calculations. This page uses lowercase calories, not the kilocalories shown as capital-C Calories on nutrition labels. Keeping that thousand-fold distinction explicit prevents a common energy-conversion mistake.

The default 1,000 joules converts to 239.006 calories. In reverse, 100 thermochemical calories converts to exactly 418.4 joules. The quick table supports common energy values, and decimal input can be used for smaller laboratory calculations.

Local energy conversion, no nutrition estimate

The calculation is performed entirely in your browser. It does not upload experimental values or fetch food data. The tool changes units only and does not estimate metabolic energy, heat losses, measurement uncertainty, or the energy content of a particular material.