⚡ Energy Converter
Convert between different energy units including joules, calories, kilowatt-hours, BTUs, electronvolts, and more. Perfect for physics, engineering, nutrition, and energy calculations.
⚡ Energy Units Reference
Joule
J
Kilojoule
kJ
Calorie
cal
Kilocalorie
kcal
Watt Hour
Wh
Kilowatt Hour
kWh
Electronvolt
eV
BTU
BTU
Table of Contents
What is an Energy Converter?
An energy converter is a tool that converts measurements of energy from one unit to another. Whether you need to convert joules to calories, kilowatt-hours to BTUs, or electronvolts to joules, an energy converter makes these calculations instant and accurate.
Energy conversions are essential in many fields including physics, chemistry, engineering, nutrition, electricity, and renewable energy. Different disciplines use different energy units, making conversions a common necessity.
Our energy converter supports 8 different units including metric units (joules, kilojoules, kilowatt-hours) and other units (calories, kilocalories, BTUs, watt-hours, electronvolts), handling everything from tiny atomic energies to large electrical power measurements.
How it Works
Our energy converter uses precise conversion factors to accurately transform values between different energy units:
- Select Units: Choose the source unit and target unit from the dropdowns
- Enter Value: Input the energy measurement you want to convert
- Instant Results: The conversion is calculated automatically in real-time
- Swap Units: Click the swap button to reverse the conversion direction
The converter works by first converting to a base unit (joules), then converting to the target unit. All conversions use standard, internationally recognized conversion factors for maximum accuracy.
Supported Units
Metric & SI Units
- Joule (J) - Base unit (SI)
- Kilojoule (kJ) - 1,000 joules
- Kilowatt Hour (kWh) - 3,600,000 joules
- Watt Hour (Wh) - 3,600 joules
Other Energy Units
- Calorie (cal) - 4.184 joules
- Kilocalorie (kcal) - 4,184 joules
- BTU (British Thermal Unit) - 1,055.06 joules
- Electronvolt (eV) - 1.60218e-19 joules
Common Use Cases
- Nutrition: Convert food energy between calories, kilocalories, and joules for diet planning and nutrition labels
- Electricity & Power: Convert electrical energy between kilowatt-hours, joules, and watt-hours for utility bills and power consumption
- Physics & Chemistry: Convert energy measurements for scientific calculations, experiments, and research
- Heating & HVAC: Convert heating energy between BTUs, joules, and kilowatt-hours for heating systems
- Renewable Energy: Convert solar and wind energy outputs between different units
- Engineering: Convert energy values for mechanical, electrical, and thermal engineering applications
- Education: Help students understand energy concepts and practice conversions
Conversion Examples
Calories to Joules
1 calorie = 4.184 joules
Example: A 200-calorie snack contains 836.8 joules. A 2,000-calorie daily diet is 8,368,000 joules (8.368 megajoules).
Kilowatt-Hours to BTUs
1 kWh = 3,412.14 BTUs
Example: A 100 kWh monthly electricity bill represents 341,214 BTUs. Useful for comparing electrical and heating energy.
Joules to Electronvolts
1 eV = 1.60218e-19 joules
Example: 1 joule equals approximately 6.242e+18 electronvolts. Used in atomic and particle physics.
BTUs to Kilowatt-Hours
1 BTU = 0.000293071 kWh
Example: A 10,000 BTU air conditioner uses approximately 2.93 kWh per hour. Useful for calculating electrical costs.
Frequently Asked Questions
In nutrition, "calorie" (capital C) actually means kilocalorie (1,000 calories). A food label showing "200 calories" means 200 kilocalories or 200,000 small calories. Our converter uses the scientific definition: 1 calorie = 4.184 joules, and 1 kilocalorie = 4,184 joules.
BTU stands for British Thermal Unit, a unit of energy used primarily in the United States for heating and cooling. One BTU is the amount of energy needed to heat one pound of water by one degree Fahrenheit. It's commonly used for air conditioners, furnaces, and heating systems.
No. All conversions happen entirely in your browser. We don't store, log, or transmit any values you enter. Your calculations are completely private.