Energy Converter
Converting energy units—such as joules, calories, or kilowatt-hours—can be challenging, especially when dealing with scientific calculations, electrical consumption, or mechanical work. Inconsistent unit systems and manual conversions often lead to errors that affect accuracy. That’s why our online Energy Converter tool is built to offer fast, accurate, and hassle-free energy unit conversions.
The Energy Converter is an easy-to-use online tool designed to simplify complex energy unit conversions. Whether you’re a scientist calculating heat energy, an engineer measuring electrical work, or a student working on physics assignments, this tool removes all the guesswork. Just input any energy value, and the converter instantly shows results across all supported units—saving time, improving accuracy, and streamlining your workflow.
Our Energy Converter supports instant conversions between the following 10 commonly used energy units:
- Kilojoule (kJ)
- Joule (J)
- Kilocalorie (kcal)
- Calorie (cal)
- Kilowatt-hour (kWh)
- Watt-hour (Wh)
- Electronvolt (eV)
- British Thermal Unit (BTU)
- US Therm
- Foot-pound (ft⋅lb)
What is Energy?
In simple words, energy is the ability to do work. According to the law of conservation of energy, energy cannot be created or destroyed; it can only be transformed from one form to another. This means that the total amount of energy in a closed system remains constant over time.
Energy is typically measured in the International System of Units (SI) using the joule (symbol: J). The joule is the fundamental unit of energy and is defined as the work done or energy transferred when a force of one newton acts on an object and displaces it by one meter in the direction of the force.
Fortunately, the advent of energy converter tools has simplified the process of converting between different energy units. These tools enable users to seamlessly switch between units such as Kilojoule, Joule, Kilocalorie, Calorie, Kilowatt-hour, Watt-hour, Electronvolt, British thermal unit, US therm, and Foot-pound.
The standard SI unit of energy is the Joule (J), but other units such as calories (used in food), kilowatt-hours (used in electricity), and BTUs (used in heating) are frequently used based on context and industry.
Here’s how some popular energy units relate to each other:
- 1 Kilojoule = 1,000 Joules
- 1 Calorie = 4.184 Joules
- 1 Kilocalorie = 1,000 Calories
- 1 Kilowatt-hour = 3.6 million Joules
- 1 BTU ≈ 1,055.06 Joules
- 1 Electronvolt ≈ 1.602 × 10⁻¹⁹ Joules
With our Energy Converter, you no longer have to remember these conversion factors. Just enter a value, and the tool instantly displays all the equivalent results—simple, accurate, and efficient.
What Are the Supported Energy Units in Our Energy Converter?
Our Energy Converter supports a complete set of energy units used in fields such as physics, nutrition, engineering, electricity billing, and mechanics. Whether you’re calculating food energy, electrical consumption, or mechanical work, this tool enables you to convert between all standard energy units accurately and instantly.
Below is a comprehensive list and explanation of the supported energy units featured in our converter, so you can make fast and reliable conversions:
1. Kilojoule (kJ)
Kilojoule is equal to 1,000 joules. It is commonly used in nutrition labeling and physical sciences to express energy content or transfer.
2. Joule (J)
Joule is the SI unit of energy, defined as the work done when a force of one newton moves an object one meter. It’s widely used across all scientific and engineering disciplines.
3. Kilocalorie (kcal)
Kilocalorie is used in food energy and nutrition, equal to 1,000 calories or approximately 4.184 kilojoules.
4. Calorie (cal)
Calorie (small calorie) is the amount of energy required to raise 1 gram of water by 1°C. 1 cal ≈ 4.184 joules. In dietary use, 1 kcal = 1 Calorie (with a capital C).
5. Kilowatt-hour (kWh)
Kilowatt-hour is commonly used in electricity billing. It equals the energy consumed when 1,000 watts are used for 1 hour. 1 kWh = 3.6 million joules.
6. Watt-hour (Wh)
Watt-hour equals the energy consumption of 1 watt over one hour. 1 Wh = 3,600 joules.
7. Electronvolt (eV)
Electronvolt is commonly used in atomic and particle physics. It is the amount of kinetic energy gained by a single electron when accelerated through one volt. 1 eV ≈ 1.602 × 10⁻¹⁹ joules.
8. British Thermal Unit (BTU)
BTU is a unit of heat used in the United States. It represents the energy needed to raise 1 pound of water by 1°F. 1 BTU ≈ 1,055.06 joules.
9. US Therm
US Therm is used to measure large quantities of natural gas. 1 Therm = 100,000 BTUs ≈ 105.5 megajoules.
10. Foot-pound (ft·lb)
Foot-pound is the energy transferred when a one-pound force moves an object one foot. It is commonly used in mechanical and civil engineering. 1 ft·lb ≈ 1.35582 joules.
Energy Conversion Formulas
From | To | Multiply By |
1 Kilojoule | Joules | 1,000 |
1 Kilocalorie | Joules | 4,184 |
1 Calorie | Joules | 4.184 |
1 Kilowatt-hour | Joules | 3,600,000 |
1 Watt-hour | Joules | 3,600 |
1 Electronvolt | Joules | 1.60218 × 10⁻¹⁹ |
1 BTU | Joules | 1,055.06 |
1 US Therm | Joules | 105,506,000 |
1 Foot-pound | Joules | 1.35582 |
1 Joule | Calories | 0.239006 |
1 Joule | Watt-hours | 0.000277778 |
1 Joule | Electronvolts | 6.242 × 10¹⁸ |
1 Joule | Foot-pounds | 0.737562 |
How to Convert Energy Units? – Explained with Examples
Energy is a fundamental concept used in physics, engineering, cooking, electricity, and more. Converting between different energy units is crucial across scientific and practical applications. This guide explains the most common energy conversions with formulas and examples for easy understanding.
1. How to Convert Kilojoules to Joules?
To convert kilojoules (kJ) to joules (J), multiply by 1,000. Formula: J = kJ × 1,000 Example: 5 kJ × 1,000 = 5,000 J
2. How to Convert Kilocalories to Calories?
To convert kilocalories (kcal) to calories (cal), multiply by 1,000. Formula: cal = kcal × 1,000 Example: 2 kcal × 1,000 = 2,000 cal
3. How to Convert Joules to Kilowatt-hours?
To convert joules to kilowatt-hours (kWh), divide by 3,600,000. Formula: kWh = J ÷ 3,600,000 Example: 7,200,000 J ÷ 3,600,000 = 2 kWh
4. How to Convert Kilowatt-hours to Watt-hours?
To convert kilowatt-hours to watt-hours, multiply by 1,000. Formula: Wh = kWh × 1,000 Example: 3 kWh × 1,000 = 3,000 Wh
5. How to Convert Electronvolts to Joules?
To convert electronvolts (eV) to joules, multiply by 1.60218 × 10−19. Formula: J = eV × 1.60218 × 10−19 Example: 1×1020 eV × 1.60218×10−19 = 16.02 J
6. How to Convert BTUs to Joules?
To convert British thermal units (BTU) to joules, multiply by 1,055.06. Formula: J = BTU × 1,055.06 Example: 10 BTU × 1,055.06 = 10,550.6 J
7. How to Convert Therms (US) to Kilojoules?
To convert therms to kilojoules, multiply by 105,505.6. Formula: kJ = therm × 105,505.6 Example: 2 therms × 105,505.6 = 211,011.2 kJ
8. How to Convert Calories to Joules?
To convert calories to joules, multiply by 4.184. Formula: J = cal × 4.184 Example: 500 cal × 4.184 = 2,092 J
9. How to Convert Watt-hours to Joules?
To convert watt-hours to joules, multiply by 3,600. Formula: J = Wh × 3,600 Example: 10 Wh × 3,600 = 36,000 J
10. How to Convert Foot-pounds to Joules?
To convert foot-pounds to joules, multiply by 1.35582. Formula: J = ft·lb × 1.35582 Example: 100 ft·lb × 1.35582 = 135.582 J
How to Use the Energy Converter Tool – Step-by-Step Guide
Use these steps to convert energy units quickly and accurately using our Energy Converter tool:
Step 1: Choose Your Input Unit: Select the unit from which you want to convert. Supported units include:
- Kilojoule (kJ)
- Joule (J)
- Kilocalorie (kcal)
- Calorie (cal)
- Kilowatt-hour (kWh)
- Watt-hour (Wh)
- Electronvolt (eV)
- British Thermal Unit (BTU)
- US Therm
- Foot-pound (ft·lb)
Step 2: Enter the Energy Value: Input your desired energy value in the field labeled “Enter Value”.
Step 3: Choose the Output Unit: Select the unit you wish to convert to. The result appears instantly.
Step 4: View Real-Time Results: The tool automatically converts the value into all other units without needing to click any buttons.
Frequently Asked Questions – Energy Converter
Q1: What is the SI unit of energy?
The joule (J) is the SI base unit of energy.
Q2: How many joules are in a kilowatt-hour?
1 kWh = 3,600,000 J.
Q3: Is a kilocalorie the same as a food Calorie?
Yes, in nutrition, 1 kilocalorie = 1 Calorie (with a capital “C”) = 1,000 calories.
Q4: What is a BTU?
BTU (British Thermal Unit) is the amount of energy needed to heat 1 pound of water by 1°F. 1 BTU = 1,055.06 J.
Q5: How many joules are in a therm?
1 therm = 105,505.6 kJ = 105,505,600 J.
Q6: Can I convert electronvolts to kilojoules?
Yes. First convert eV to J using 1.60218 × 10−19, then divide by 1,000 to get kJ.
Q7: What’s the difference between watt-hours and kilowatt-hours?
1 kWh = 1,000 Wh. Both are used to measure electrical energy.
Q8: Is this tool mobile compatible?
Yes, it’s fully responsive and works on all devices.
Q9: Can I use this for scientific research?
Absolutely. The tool supports precise and high-value conversions ideal for technical fields.
Q10: Is a foot-pound a unit of energy or torque?
It can be both, but in this context, it’s used as a unit of energy: 1 ft·lb = 1.35582 J.
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Conclusion: Energy conversion is essential across physics, engineering, electricity billing, nutrition, and more. Our Energy Converter simplifies the process by supporting a wide range of units like kilojoule, joule, kilocalorie, calorie, kilowatt-hour, watt-hour, electronvolt, British thermal unit (BTU), US therm, and foot-pound. Whether you’re calculating food energy or electrical consumption, this tool delivers fast, precise, and user-friendly conversions. Try it now to make energy calculations easier than ever!
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