Energy Converter
Convert between units of energy, from joules and calories to watt hours, kilowatt hours, and BTU. The result updates as you type.
About Energy Converter
This energy converter spans science, nutrition, and electricity, including joules, calories, the kilocalories on food labels, watt hours, kilowatt hours on your power bill, and BTU used in heating and cooling.
Frequently Asked Questions
Are food calories the same as calories here?
A food Calorie with a capital C is actually a kilocalorie. Use the kilocalorie unit to match nutrition labels.
How many joules are in a kilowatt hour?
One kilowatt hour is 3,600,000 joules, which is why it is a convenient unit for measuring household energy use.
Is the tool private and free?
Yes. Every conversion runs in your browser, nothing is uploaded, and the tool is free with no signup.
About Matt George
I'm Matt George, a software engineer in the startup space. I run my own shop building software for early-stage founders, and I love making free tools and experiences that people actually use. Enjoy using Energy Converter!