Energy ConverterBy AiToolsWeb / September 21, 2026 From: Joule (J) Kilojoule (kJ) Gram Calorie (cal) Kilocalorie (kcal) Watt-hour (Wh) Kilowatt-hour (kWh) BTU = To: Joule (J) Kilojoule (kJ) Gram Calorie (cal) Kilocalorie (kcal) Watt-hour (Wh) Kilowatt-hour (kWh) BTU