Energy Converter: Convert Between Energy Units

Energy comes in many forms and units — joules, calories, kilowatt-hours, BTUs, therms, and more. Our Energy Converter handles conversions between all common energy units used in science, cooking, electricity billing, and HVAC. Whether you are converting food calories to joules for a physics problem or comparing natural gas bills in therms versus BTUs, get accurate energy conversions instantly.

Key conversions: 1 joule (J) = 0.239 calories. 1 kilocalorie (food Calorie) = 4,184 joules. 1 kilowatt-hour (kWh) = 3.6 million joules. 1 BTU = 1,055 joules. 1 therm (natural gas) = 100,000 BTUs. The converter handles all of these and more, including electronvolts (eV) for physics and foot-pounds for engineering.

Use the Energy Converter to understand your electricity bill (kWh to joules), compare food energy (calories to kilojoules), convert HVAC ratings (BTU to kWh), and solve physics and chemistry problems. Also check our BTU Calculator for heating and cooling capacity and our Power Converter for power unit conversions.