Energy Converter

How to use the Energy Converter

Convert common scientific, electrical, thermal, and food-energy units using defined or standard conversion values.

Convert energy quantities among joules, kilojoules, watt-hours, kilowatt-hours, calories, and selected thermal units. It is useful for comparing electrical, food, and mechanical energy labels when definitions are explicit.

The conversion runs locally using the stated factors or formulas. Keep enough precision for the task and verify regulated or engineering work against its controlling standard.

1. Enter an energy amount.
2. Choose the source and target units.
3. Fieldlet converts through joules and displays the equivalent amount.

Last reviewed for accuracy: 2026-09-01

Worked examples

How the result is produced

The converter uses joules as the base. A watt-hour is power multiplied by time, while calorie labels may refer to small calories or food kilocalories depending on context.

• 1 watt-hour = 3,600 joules
• 1 kilowatt-hour = 3.6 megajoules
• 1 dietary Calorie is commonly 1 kilocalorie

Energy and power answer different questions

Energy describes an accumulated amount, while power describes the rate at which energy is transferred. A kilowatt-hour is therefore an energy unit even though its name contains the power unit kilowatt.

• 1 Wh = 3,600 J.
• 1 kWh = 3.6 MJ.
• Cost requires an energy price; runtime also requires device power.

Limitations and common mistakes

• Thermal-unit definitions can vary slightly by reference condition.
• Energy conversion does not calculate efficiency, cost, power demand, or emissions.

Common questions