ΣMyCalc
ΣMyCalc

Energy Converter

Convert between joules, calories, kilowatt-hours, BTU, and other energy units.

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Conversion Result

1000 Joules (J)

→

4183.99538087

Calories (cal)

⚡ Energy References

1 kWh = 3.6 million joules

1 BTU = 1,055 joules

1 cal = 4.184 joules

1 kcal = 4,184 joules

📊 Common Uses

Electricity: Measured in kWh

Food/Diet: Measured in calories (kcal)

Physics/Science: Measured in joules

Heating: Measured in BTU

How to Use the Energy Calculator

Enter an energy value, select the current unit (joules, calories, kilowatt-hours, BTU, etc.), choose your target unit, and get instant conversion. Used in physics, chemistry, and engineering.

Formula

All energy values convert through joules (base SI unit). value_in_j = input × from_factor; result = value_in_j ÷ to_factor.

History & Interesting Facts

💡 Did You Know?

A food calorie (kcal) is different from a scientific calorie. Food calories are kilocalories: 1 food cal = 1,000 small calories.

Origin & History

The joule is the SI unit of energy. 1 joule is the energy needed to apply 1 newton of force over 1 meter. Named after James Prescott Joule.

Fascinating Facts

  • 1

    1 kilowatt-hour (kWh) = 3.6 million joules

  • 2

    1 BTU = 1,055 joules

  • 3

    1 food calorie = 4,184 joules

  • 4

    1 megajoule = 277.8 Watt-hours

  • 5

    Electricity is often measured in kilowatt-hours

  • 6

    Food energy is measured in kilocalories

Frequently Asked Questions

What is a joule?

A joule is the SI unit of energy or work. 1 joule = 1 watt × 1 second, or the energy to lift 1 kilogram 10 centimeters.

How much is a kilowatt-hour in joules?

1 kilowatt-hour (kWh) = 3,600,000 joules. This is the standard unit for electricity billing.

What is the difference between calories and kilocalories?

1 food calorie = 1 kilocalorie (kcal) = 1,000 small calories. Food packages list kilocalories as "calories".

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