Universal Converters

Energy Converter

Convert between 70+ energy units — from atomic-scale electron volts to industrial power usage.

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Popular Conversions

J → CAL CAL → J kWh → J BTU → J

🔥 Food Energy

1 kcal

4,184 J

⚡ Electricity

1 kWh

3.6 MJ

🌡️ Thermal

1 BTU

1,055 J

⚛️ Atomic

1 eV

1.6×10⁻¹⁹ J

Popular Energy Conversions

Calories to Joules

1 cal = 4.184 J

Joules to Calories

1 J = 0.239 cal

1 J = 2.78×10⁻⁷ kWh

Kilocalories to kJ

1 kcal = 4.184 kJ

Kilojoules to kcal

1 kJ = 0.239 kcal

Watt-hours to Joules

Joules to Watt-hours

1 J = 0.000278 Wh

1 BTU = 1,055 J

Energy Facts & Science

One food Calorie (kcal) equals exactly 4,184 joules.

A kilowatt-hour is the amount of energy used by a 1,000-watt device running for one hour.

Electron volts are commonly used to measure atomic and subatomic energy levels.

Home & Energy

Power vs Energy: The Ultimate Guide to Your Electric Bill

Finally understand the difference between kW and kWh. A deep dive into electric bills, horsepower history, solar math, and why your hair dryer is an energy vampire.

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Universal Converters Energy Converter – Accurate tool supporting 70+ energy units used in physics, engineering, electricity billing, HVAC, and nutrition.

Convert joules to calories, kWh to joules, BTU to kWh, and all common energy measurements instantly.