Energy Converter

What is energy converter?

An energy converter changes between units used for heat, electricity and food, such as joules, calories, kilowatt hours and BTU. It helps when comparing bills, appliances and diets.

A food Calorie with a capital C is a kilocalorie, which equals 4,184 joules.

How to use the energy converter

1. Enter the value.
2. Choose the unit you have and the unit you want.
3. Read the result and the table of all units.

How the energy converter works

Each value is converted to joules using exact factors, such as 4.184 joules per calorie, 3,600 per watt hour and 1,055.056 per BTU. The result is divided by the target factor.

Worked example

Common uses of the energy converter

• Comparing electricity bills.
• Reading nutrition labels.
• Sizing heaters and air conditioners.
• Physics and chemistry homework.
• Energy efficiency checks.

Tips and common mistakes

Electric bills use kilowatt hours, while gas often uses therms or BTU.

Use the table to compare many units at once.

Background: what to know before you rely on it

Energy is the ability to do work, and the joule is its SI unit. Different fields grew their own units: nutrition used the calorie, heating used the BTU, and electricity used the kilowatt hour. A kilowatt hour is the energy of a one kilowatt device running for one hour, which is the unit on most household power bills. Converting among them lets you compare, for example, the cost of heating with gas versus electricity.

Private, free and fast

This tool runs entirely in your browser. What you type or choose is not uploaded to a server and is not saved after you close the page, which keeps it fast and private. It is free to use as often as you like. See more in all converters, or browse the full list of tools.

Related tools

Results are for information and education. For legal, financial, medical or security decisions, check with a qualified professional. Check critical conversions with an official source.