Energy Converter - Convert Joules, Calories, BTU, kWh & More Units
Result:
1000 kJ = 239.00573614 kcal
How Energy Conversion Works
Input Value
Enter energy value
Select Units
Choose from and to units
Convert
Apply conversion formula
Energy Formulas
Basic Formulas
E = mc² (Mass-energy equivalence)
E = ½mv² (Kinetic energy)
E = mgh (Potential energy)
Unit Conversions
1 kJ = 1000 J
1 kcal = 4184 J
1 kWh = 3.6 MJ
Energy Conversion Table
| Joules (J) | Kilojoules (kJ) | Calories (cal) | kWh |
|---|---|---|---|
| 1,000 | 1 | 239 | 0.000278 |
| 5,000 | 5 | 1,195 | 0.001389 |
| 10,000 | 10 | 2,390 | 0.002778 |
| 50,000 | 50 | 11,950 | 0.013889 |
| 100,000 | 100 | 23,901 | 0.027778 |
| 500,000 | 500 | 119,503 | 0.138889 |
| 1,000,000 | 1,000 | 239,006 | 0.277778 |
| 5,000,000 | 5,000 | 1,195,029 | 1.388889 |
| 10,000,000 | 10,000 | 2,390,057 | 2.777778 |
| 50,000,000 | 50,000 | 11,950,287 | 13.888889 |
| 100,000,000 | 100,000 | 23,900,574 | 27.777778 |
| 500,000,000 | 500,000 | 119,502,868 | 138.888889 |
| 1,000,000,000 | 1,000,000 | 239,005,736 | 277.777778 |
| 5,000,000,000 | 5,000,000 | 1,195,028,681 | 1388.888889 |
| 10,000,000,000 | 10,000,000 | 2,390,057,361 | 2777.777778 |
Energy Units Progression Chart
1 kJ
10 kJ
100 kJ
1 MJ
10 MJ
100 MJ
Practice Problems
Problem 1:
Convert 5000 J to kJ
Solution: 5000 ÷ 1000 = 5 kJ
Problem 2:
Convert 2 kcal to J
Solution: 2 × 4184 = 8368 J
Problem 3:
Convert 1 kWh to MJ
Solution: 1 × 3.6 = 3.6 MJ
Problem 4:
Convert 1000 BTU to kJ
Solution: 1000 × 1.055 = 1055 kJ
Problem 5:
Convert 500 cal to kJ
Solution: 500 × 4.184 ÷ 1000 = 2.092 kJ
What is Energy?
Energy is the power to do work or make things happen. It comes in many forms and can change from one type to another. Our energy converter helps you switch between different energy units with ease. Whether you need a joule converter, calorie converter, BTU converter, or kWh converter, this tool handles all energy units.
Energy follows a simple rule: it cannot be made or destroyed, only changed from one form to another. This rule is called the law of conservation of energy. When you use our energy converter, you are just changing how we measure the same amount of energy. This physics calculator makes thermodynamics calculations simple for everyone.
Types of Energy
- • Kinetic energy (things that move)
- • Potential energy (stored energy)
- • Heat energy (warmth)
- • Chemical energy (in food and gas)
- • Electrical energy (in wires and batteries)
- • Nuclear energy (from atoms)
- • Solar energy (from the sun)
- • Wind energy (from moving air)
Energy Units We Convert
- • Joule (J) - basic science unit
- • Calorie (cal) - food energy unit
- • BTU - heating and cooling unit
- • kWh - electricity bill unit
- • Watt-hour (Wh) - small device unit
- • Kilojoule (kJ) - larger amounts
- • Kilocalorie (kcal) - food labels
- • Megajoule (MJ) - very large amounts
Energy Units Explained Simply
Joule (J) - The Basic Unit
The joule is the main energy unit in science. It got its name from James Prescott Joule, a famous scientist. One joule is about the energy you need to lift a small apple one meter up. Our joule converter makes it easy to change joules to other energy units. Scientists use joules because they work well with physics calculations.
Calorie (cal) - Food Energy
A calorie measures the energy in food. It is the energy needed to warm one gram of water by one degree. Food packages show calories to tell you how much energy the food gives your body. Our calorie converter helps you understand food energy better. When people talk about diet calories, they usually mean kilocalories.
Kilowatt-hour (kWh) - Electric Bills
This unit shows up on your electric bill every month. One kWh is the energy a 1000-watt machine uses in one hour. A hair dryer uses about 1 kWh if you run it for one hour. Our kWh converter helps you understand your electricity use and compare it to other energy forms.
BTU - Heating and Cooling
BTU stands for British Thermal Unit. It measures heat energy. One BTU is the energy needed to warm one pound of water by one degree Fahrenheit. Air conditioners and heaters show their power in BTU. Our BTU converter helps you compare different heating and cooling systems.
Watt-hour (Wh) - Small Devices
A watt-hour is much smaller than a kilowatt-hour. Phone batteries and small devices use watt-hours. Your phone battery might hold 15 Wh of energy. Laptop batteries often hold 50-100 Wh. This physics calculator can convert watt-hours to any other energy unit you need.
Foot-pound (ft⋅lbf) - Work Energy
This unit measures work energy. One foot-pound is the energy needed to lift one pound up one foot. Construction workers and engineers use this unit. It helps them calculate how much energy machines need to do their jobs. Our energy converter includes this unit for technical work.
How to Use Our Energy Converter
Our energy converter is designed to be simple and fast. Whether you need a joule converter, calorie converter, BTU converter, or kWh converter, the process is the same. This physics calculator handles all thermodynamics conversions automatically with precise results.
Step 1: Enter Your Energy Value
Type the energy amount you want to convert in the "Value" box. You can use whole numbers, decimals, or scientific notation. For example, type "1000" to convert 1000 units of energy, or "2.5" for fractional amounts.
Tip: The energy converter accepts any positive number, including very large or very small values.
Step 2: Select Starting Unit
Pick the unit you are starting with from the "From" dropdown menu. Choose from joules, calories, BTU, kWh, and many other energy units. If you have joules, select "Joule (J)". For food energy, select "Calorie (cal)" or "Kilocalorie (kcal)".
Tip: Look for the unit symbol in parentheses to make sure you select the right one.
Step 3: Choose Target Unit
Select the unit you want to convert to from the "To" dropdown menu. The physics calculator will instantly show you the result as you make your selection. You can convert between any energy units in our list.
Tip: The conversion happens automatically - no need to click a convert button.
Step 4: Use Your Result
The converted value appears automatically in the result box with high precision. You can copy this number for your calculations, homework, or work projects. The energy converter shows results to 8 decimal places for accuracy.
Tip: You can print the page or download results for future reference.
Energy in Everyday Life
Understanding energy units becomes easier when you see real examples. Our energy converter helps you compare these different energy amounts. Use the joule converter, calorie converter, BTU converter, or kWh converter to see how these examples relate to each other.
Food Energy Examples
• One banana: 420 kJ (100 kcal)
• Slice of bread: 315 kJ (75 kcal)
• Glass of milk: 630 kJ (150 kcal)
• Medium apple: 350 kJ (85 kcal)
• Cup of rice: 840 kJ (200 kcal)
• Chocolate bar: 1050 kJ (250 kcal)
• Can of soda: 590 kJ (140 kcal)
Home Energy Use
• LED light bulb (1 hour): 10 Wh
• Regular light bulb (1 hour): 60 Wh
• TV (1 hour): 150 Wh
• Laptop (1 hour): 50 Wh
• Washing machine: 2 kWh
• Air conditioner (1 hour): 3 kWh
• Electric oven (1 hour): 2.5 kWh
Transportation Energy
• Walking (1 mile): 300 kJ
• Bicycle (1 mile): 75 kJ
• Electric scooter (1 mile): 150 kJ
• Electric car (1 mile): 1.1 MJ
• Gas car (1 mile): 3.5 MJ
• Motorcycle (1 mile): 1.8 MJ
• Bus (per person, 1 mile): 1.2 MJ
Energy Conversion Tips & Tricks
Master energy conversion with these helpful tips. Our energy converter makes calculations easy, but understanding these concepts helps you use the joule converter, calorie converter, BTU converter, and kWh converter more effectively. These physics calculator tips improve your thermodynamics understanding.
Essential Conversion Facts
- • 1 kJ = 1000 J (kilo means thousand)
- • 1 MJ = 1,000,000 J (mega means million)
- • 1 kcal = 4.184 kJ (food calories)
- • 1 kWh = 3.6 MJ (electricity units)
- • 1 BTU = 1.055 kJ (heating units)
- • 1 Wh = 3.6 kJ (small device energy)
Quick Mental Estimates
- • 1 calorie ≈ 4 joules (easy to remember)
- • 1 BTU ≈ 1000 joules (round number)
- • 1 Wh ≈ 3600 joules (1 hour = 3600 seconds)
- • 1 kWh ≈ 860 kcal (daily food energy)
- • 1 kcal ≈ 1 Cal (food label calories)
- • 1 MJ ≈ 278 Wh (useful for batteries)
Unit Prefixes Guide
- • k (kilo) = 1,000 times bigger
- • M (mega) = 1,000,000 times bigger
- • G (giga) = 1,000,000,000 times bigger
- • m (milli) = 1,000 times smaller
- • μ (micro) = 1,000,000 times smaller
Common Mistakes to Avoid
- • Don't confuse cal with kcal (1000x difference)
- • Remember kWh is energy, not power
- • BTU can be different types (IT, thermochemical)
- • Check if calories are small cal or large Cal
- • Don't mix up Wh and W (energy vs power)
- • Watch out for different BTU definitions
Best Practices
- • Double-check your input values
- • Use appropriate precision for your needs
- • Consider the context of your conversion
- • Keep track of significant figures
- • Verify results with known examples
- • Use consistent units throughout calculations
When to Use Each Unit
- • Joules: Scientific calculations
- • Calories: Food and nutrition
- • BTU: Heating and cooling systems
- • kWh: Electricity bills and usage
- • Wh: Small batteries and devices
Daily Uses of Energy Conversion
Energy conversion happens everywhere in daily life. Our energy converter helps you understand these processes by changing between different energy units. Use the joule converter, calorie converter, BTU converter, or kWh converter to make sense of energy in your daily activities.
Nutrition & Health
Food labels show energy in calories and kilojoules. Our calorie converter helps you understand how much energy different foods provide to your body. This physics calculator makes it easy to compare foods and plan meals.
Example: Convert 2000 kcal daily intake to kJ to understand international food labels.
Home Energy Bills
Electricity bills measure consumption in kilowatt-hours. Our kWh converter helps you convert to other units to compare energy costs and understand your usage better. Track your thermodynamics efficiency at home.
Example: Convert 500 kWh monthly use to MJ to compare with gas heating energy.
Car Fuel Efficiency
Vehicle fuel efficiency calculations use energy content measurements. Our energy converter helps you compare different fuel types and electric vehicle efficiency using the same energy units.
Example: Compare gasoline MJ/liter with electric car kWh/mile efficiency.
Solar Panel Output
Solar panel ratings specify energy production capacity in watts and kilowatt-hours. Use our kWh converter to understand daily and monthly energy generation in different units.
Example: Convert 30 kWh daily solar output to MJ for energy storage calculations.
Battery Capacity
Battery specifications use energy storage measurements in watt-hours or amp-hours. Our energy converter helps you compare different battery types and capacities using consistent energy units.
Example: Convert phone battery 15 Wh to joules for physics calculations.
Heating & Cooling
HVAC systems are rated in BTU for heating and cooling capacity. Our BTU converter helps you convert to watts or other units to compare system efficiency and understand thermodynamics performance.
Example: Convert 12000 BTU air conditioner to kW for electrical load planning.
Thermodynamics Made Simple
Thermodynamics is the science of energy and heat. Our physics calculator helps you understand these concepts by converting between different energy units. Whether you need a joule converter or calorie converter, understanding thermodynamics makes energy conversion easier.
First Law of Thermodynamics
Energy cannot be created or destroyed, only changed from one form to another. This is why our energy converter works - we are just changing how we measure the same energy.
Example: When you eat food (chemical energy), your body converts it to heat and movement (kinetic energy).
Second Law of Thermodynamics
Heat always flows from hot things to cold things. Energy tends to spread out and become less useful over time. This is why machines are never 100% efficient.
Example: A car engine converts gas energy to motion, but some energy becomes waste heat.
Heat vs Temperature
Heat is energy moving between objects. Temperature measures how hot something is. You can have a lot of heat at low temperature, or little heat at high temperature.
Example: A swimming pool at 80°F has more heat energy than a cup of boiling water.
Energy Efficiency
Efficiency shows how much useful energy you get out compared to what you put in. No machine is 100% efficient because some energy always becomes waste heat.
Example: LED lights are 90% efficient, while old bulbs are only 10% efficient.
How Energy Conversion Works
Energy conversion is the process of changing energy from one form to another. Our energy converter uses scientific formulas to change between energy units. Understanding these principles helps you use the joule converter, calorie converter, BTU converter, and kWh converter more effectively.
Mechanical Energy Conversion
Mechanical energy includes kinetic energy (moving things) and potential energy (stored energy). When you lift something up, you give it potential energy. When you drop it, that becomes kinetic energy.
Formula: Kinetic Energy = ½ × mass × velocity²
Thermal Energy Conversion
Heat energy moves from hot objects to cold objects. This is how heaters warm rooms and how your body stays warm. BTU and calories measure this type of energy.
Formula: Heat Energy = mass × specific heat × temperature change
Electrical Energy Conversion
Electrical energy powers our homes and devices. Generators convert mechanical energy to electrical energy. Motors convert electrical energy back to mechanical energy. kWh measures electrical energy use.
Formula: Electrical Energy = Power × Time
Chemical Energy Conversion
Chemical energy is stored in food, batteries, and fuel. Your body converts food energy to heat and motion. Car engines convert gas energy to motion. Calories measure food energy.
Formula: Chemical Energy = bonds broken - bonds formed
Frequently Asked Questions
What is the difference between energy and power?
Energy is the total amount of work that can be done, while power is how fast energy is used. Think of energy as the total amount of water in a bucket, and power as how fast you pour it out. Energy is measured in joules or calories, while power is measured in watts. Our physics calculator helps you convert energy units, not power units.
Why are there so many different energy units?
Different energy units developed for different purposes. Calories are used for food because they relate to heating water. BTU is used for heating systems. kWh is used for electricity billing. Each unit makes calculations easier in its specific field. Our energy converter includes all major energy units so you can switch between them easily.
How accurate is this energy converter?
Our energy converter uses standard conversion factors accepted by scientific organizations worldwide. The results are accurate to 8 decimal places, which is more than enough for most practical uses. For scientific research, always verify with official standards. The joule converter, calorie converter, BTU converter, and kWh converter all use precise conversion factors.
Can I convert between all energy units?
Yes, all energy units can be converted to each other because they all measure the same thing - energy. Our converter includes the most common units used in science, engineering, nutrition, and daily life. Just select your starting unit and target unit. The physics calculator handles thermodynamics calculations automatically.
What is the most commonly used energy unit?
The joule is the standard scientific unit for energy. However, in daily life, people use different units: calories for food, kWh for electricity, and BTU for heating. The best unit depends on what you are measuring and your location. Our energy converter lets you work with any unit you prefer.
How do I choose the right energy unit?
Choose the unit that makes sense for your situation. Use calories for food energy, kWh for electricity, BTU for heating and cooling, and joules for science work. Our energy converter makes it easy to switch between units when needed. The physics calculator shows results in the unit you select.
Is this energy converter free to use?
Yes, our energy converter is completely free to use. You can convert between joules, calories, BTU, kWh, and all other energy units without any cost. The joule converter, calorie converter, BTU converter, and kWh converter are all available 24/7. No registration or download required.