About this site

This site was built to make energy numbers easier to compare. Many food labels show energy in kilojoules (kJ), while many apps and international resources use calories (kcal). The calculators here help you translate between the two quickly — without doing manual math.

We focus on clarity, speed, and correctness. If something looks confusing or you spot an issue, please tell us — feedback directly improves the tool.

Privacy is simple here: the calculator runs in your browser. We don’t ask for logins, and we don’t store your inputs. The numbers you enter are used only to produce your result.

We keep pages lightweight so they load fast on mobile — the most common way people use a quick converter.

Conversions use the standard relationship between calories (kcal) and kilojoules (kJ): 1 kcal = 4.184 kJ. We calculate using full precision and round results for readability.

Where we show the “8,700 kJ per day” reference, it’s used as a general label reference — not personalised dietary advice. Individual needs vary by age, body size, and activity level.