Energy Converter
Convert between joules, calories, kilowatt-hours, and more with precision. Free online energy converter tool.
This free tool allows you to convert between different units of energy including joules (J), calories (cal), kilowatt-hours (kWh), and more. Simply enter your value and select the units to convert from and to.
How This Tool Works
Our energy converter uses precise conversion factors to convert between different units of energy:
- 1 Kilojoule (kJ) = 1,000 Joules (J)
- 1 Calorie (cal) = 4.184 Joules (J)
- 1 Kilocalorie (kcal) = 4,184 Joules (J)
- 1 Watt-hour (Wh) = 3,600 Joules (J)
- 1 Kilowatt-hour (kWh) = 3,600,000 Joules (J)
The calculator ensures accuracy by first converting the input value to joules (the base unit), then converting to the desired output unit.
Frequently Asked Questions
What's the difference between calories and kilocalories?
A kilocalorie (kcal) is equal to 1,000 calories. In nutrition, what we commonly call a "calorie" is actually a kilocalorie. One kilocalorie is the amount of energy needed to raise the temperature of 1 kilogram of water by 1°C.
Why do we use kilowatt-hours for electricity bills?
Kilowatt-hours (kWh) are used for electricity billing because they represent a practical amount of energy for household use. One kWh is the energy used by a 1,000-watt appliance running for one hour.
How accurate is this energy converter?
Our energy converter provides results with 6 decimal places of precision, using standard conversion factors recognized by international measurement organizations.
Tips and Best Practices
For the most accurate energy conversions:
- Use joules for scientific calculations
- Use kilocalories for nutritional calculations
- Use kilowatt-hours for electrical energy
- Consider the scale of your measurement when choosing units