Energy Converter
Energy Converter translates J, kJ, cal, kcal, Wh, and kWh through joules. The calorie factor is the thermochemical calorie, 4.184 J, and kcal is 4184 J. Food-label Calories often mean kilocalories. The tool does not calculate power, billing cost, metabolic availability, or efficiency losses.
Runs locally — files stay on your deviceHow many joules are in one kilowatt-hour?
3,600,000 joules.
Energy and power are related but not interchangeable
A watt is one joule per second, so one watt-hour is 3600 joules. The page uses 1 cal = 4.184 J and 1 kcal = 4184 J.
How it works
The source energy is normalized to joules and scaled to the destination unit.
Key concepts
Power is a rate
Energy = power × time.
Calorie naming is context-sensitive
A nutrition Calorie commonly denotes one kilocalorie.
When to use it
- Compare electricity and joule quantities.
- Translate thermochemical calories.
- Convert kWh into raw energy.
When not to use it
- Do not convert watts to joules without a duration.
- Do not assume food energy equals usable metabolic energy for every person.
- Do not derive cost without tariffs and losses.
Worked examples
Kilowatt-hour
- Input
1 kWh- Expected output
3.6 MJ
1000 W × 3600 s.
Thermochemical calorie
- Input
1 cal- Expected output
4.184 J
The stored definition is used.
Food-label unit
- Input
100 kcal- Expected output
418.4 kJ
One kcal equals 4184 J.
Common mistakes
Converting watts directly
Watts lack duration. Correction: Multiply power by elapsed time.
Confusing cal and kcal
They differ by a factor of 1000. Correction: Check capitalization and context.
Calling kWh power
It is energy. Correction: Use kW for power.
Best practices
- State the calorie convention.
- Keep rate and accumulated energy separate.
- Include efficiency and tariff assumptions in applied calculations.
Related operations and differences
Area Converter
Choose Area Converter when you need to convert common metric and imperial areas.; use Energy Converter specifically for convert.
Data Storage Converter
Choose Data Storage Converter when you need to convert decimal and binary storage units.; use Energy Converter specifically for convert.
Fuel Economy Converter
Choose Fuel Economy Converter when you need to convert MPG, L/100 km and km/L.; use Energy Converter specifically for convert.
Length Converter
Choose Length Converter when you need to convert metric and imperial length units.; use Energy Converter specifically for convert.
Power Converter
Choose Power Converter when you need to convert watts, kilowatts and horsepower.; use Energy Converter specifically for convert.
Pressure Converter
Choose Pressure Converter when you need to convert pascals, bar, PSI and atmospheres.; use Energy Converter specifically for convert.
Limitations and privacy
- Thermochemical calorie only.
- No BTU, electronvolt, cost, efficiency, or metabolic model.
- Does not convert power without time.
Values are converted locally in this browser and are not uploaded.
Frequently asked questions
How many J are in 1 Wh?
3600.
Is kWh power?
No, it is energy.
How many cal are in 1 kcal?
1000.
Which calorie is used?
The thermochemical calorie.