The calorie converter is a free online tool that helps you convert between health units quickly and accurately. It supports 5 units including Calorie (small) (cal), Kilocalorie (food calorie) (kcal), Joule (J), Kilojoule (kJ), Watt-hour (Wh). The core conversion formula is: 1 kcal = 1000 cal = 4184 J. For example, 1 Calorie (small) equals approximately 0.001 Kilocalorie (food calorie). Conversely, 1 Kilocalorie (food calorie) equals approximately 1,000 Calorie (small). Common conversions: 5 cal = 0.005 kcal, 10 cal = 0.01 kcal, 25 cal = 0.025 kcal, 50 cal = 0.05 kcal, 100 cal = 0.1 kcal. This converter is useful for students, engineers, scientists, and professionals who need accurate health unit conversions. Whether you are working on homework, technical specifications, research data, or everyday measurements, this tool provides instant, reliable results. All conversions are calculated relative to a single base unit for consistency and precision across all supported units. Food calories are actually kilocalories (kcal). A typical adult needs 2000-2500 calories per day.