Energy Converter
Convert between common energy units instantly. Ideal for physics, nutrition, engineering, and electricity billing calculations.
How to Use the Energy Converter
Converting between energy units is quick and accurate:
- Enter a numeric value in the input field. Decimals and scientific notation values are supported.
- Select the source unit from the dropdown (Joules, Calories, kWh, BTU, etc.).
- View all conversions in the results table. Calculations happen instantly as you type.
- Click Copy next to any result to copy the value to your clipboard.
About Energy Units
Energy is the capacity to do work and is one of the most fundamental concepts in physics. The SI unit of energy is the Joule (J), named after James Prescott Joule. One Joule equals the work done by a force of one Newton moving an object one meter. In nutrition, energy is measured in kilocalories (often labeled simply as "Calories" on food packaging), where 1 kcal = 4,184 J.
Electricity consumption is measured in kilowatt-hours (kWh), where 1 kWh = 3,600,000 J. The British Thermal Unit (BTU) is used in HVAC and heating industries. Electronvolts (eV) are used in atomic and particle physics. Understanding energy unit conversions is vital for comparing fuel sources, calculating electricity costs, managing nutrition, and engineering design.
Frequently Asked Questions
One thermochemical calorie equals exactly 4.184 Joules. To convert Joules to calories, divide by 4.184. Note that food "Calories" (capital C) are actually kilocalories (1 kcal = 4,184 J).
A calorie (cal, lowercase) is a small unit of energy equal to 4.184 Joules. A Calorie (Cal, uppercase) used on food labels is actually a kilocalorie (kcal), equal to 1,000 small calories or 4,184 Joules.
Multiply kilowatt-hours by 3,412.14 to get BTU. For example, 1 kWh = 3,412.14 BTU. This conversion is commonly used in HVAC and energy billing.
An electronvolt (eV) is the energy gained by a single electron moving through an electric potential difference of one volt. It equals 1.602 × 10⁻¹⁹ Joules and is commonly used in particle physics and chemistry.