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Energy Converter - Convert Between Joules, Cal, kWh, BTU, eV Online Free
Convert between joules, calories, kWh, BTU, and electronvolts.
What Is a Energy Converter?
An energy converter converts between different energy measurement units.
Supported Units
- Joule (J) — SI unit. 1 J = 1 N.m.
- Kilojoule (kJ) — 1000 J. Food labels.
- Calorie (cal) — 4.184 J. Chemistry.
- Kilocalorie (kcal) — 1000 cal = 1 food Cal.
- Kilowatt-hour (kWh) — 3.6 MJ. Electricity billing.
- BTU — 1055.06 J. HVAC/gas.
- Electronvolt (eV) — 1.602e-19 J. Particle physics.
How Does Energy Converter Work?
1 J = 0.239 cal, 1 cal = 4.184 J, 1 kWh = 3.6 MJ, 1 BTU = 1055.06 J.
How to Use This Tool
- Enter a numeric value — Type the measurement you want to convert.
- Select the source unit — Choose the unit you are converting from.
- Read the results — The tool instantly displays equivalents in every supported unit.
Try our Power Converter or Weight Converter.
Use Cases
Nutrition
Convert between cal, kcal, and kJ.
Home Energy
Compare kWh and BTU usage.
Science
Convert between J and eV.
Related Tools
- Power Converter - W, kW, HP, BTU/h.
- Weight Converter - kg, lb, oz, g.
- Pressure Converter - Pa, bar, psi, atm.
Privacy
All calculations are performed entirely in your browser using JavaScript. No data is sent to our servers. We do not store, log, or share any values you enter.
Uses thermochemical cal (1 cal = 4.184 J). Food Calories = kilocalories.
AI Overview
An energy converter converts between J, kJ, cal, kcal, kWh, BTU, and eV.
Quick Answers
J in 1 cal?
A:4.184.
J in 1 kWh?
A:3,600,000 (3.6 MJ).
BTU in 1 kWh?
A:~3412.
How to Use the Energy Converter - Convert Between Joules, Cal, kWh, BTU, eV Online Free
- Type the energy value you want to convert into the input field. Decimals and large numbers are supported.
- Choose your starting unit from the dropdown menu - for example watt-hours (Wh), kilowatt-hours (kWh), or joules (J).
- See the value converted into every supported unit instantly, including kilojoules, or megawatt-hours.
Benefits
- Instant Multi-Unit Conversion
- Multiple Unit Systems
- 100% Free to Use
- Works on Any Device
Common Mistakes
- Food Cal (kcal) = 1000 scientific cal
- 1 kWh = 3.6 MJ not 3600 kJ
- Mix up joules (energy) vs watts (power)
- Different calorie definitions exist
Professional Tips
- Food Cal = 1000 scientific cal
- 1 kWh = 1000W for 1 hour
- Avg US household: ~10,500 kWh/yr
- eV used in particle/semiconductor physics
Common Use Cases
Nutrition
Convert cal/kcal/kJ for diet.
Home Energy
Compare kWh and BTU.
Science
Convert J/eV for research.
Engineering
Convert energy units.
Related Concepts
Joule (J)
SI unit. 1 J = 1 N.m.
Kilojoule (kJ)
1000 J. Food labels.
Calorie (cal)
4.184 J. Chemistry.
Kilocalorie (kcal)
1000 cal = 1 food Cal.
Kilowatt-hour (kWh)
3.6 MJ. Electricity billing.
BTU
1055.06 J. HVAC/gas.
Electronvolt (eV)
1.602e-19 J. Particle physics.
Frequently Asked Questions
References
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