에너지 변환기
무료 에너지 변환기 — 줄, 킬로줄, 킬로와트시, 칼로리, 킬로칼로리, BTU 및 전자볼트. 물리학, 영양학, 공학용.
Runs in your browserUpdated Apr 26, 2026
Energy converter
All energy conversions
Joule
1000 J
Watt hour
0.2777777778 Wh
Kilowatt hour
0.0002777777778 kWh
Calorie
239.0057361 cal
Kilocalorie
0.2390057361 kcal
BTU
0.9478133945 BTU
Foot-pound
737.5621212 ft·lb
자주 묻는 질문
›Calorie or kilocalorie on food labels?
On food labels in the US the 'Calorie' (capital C) is actually a kilocalorie (1,000 small calories). Most other countries label them as kcal or kJ to avoid confusion.
›How much is 1 kWh?
1 kilowatt-hour = 3.6 million joules. It's the energy you'd use running a 1,000 W appliance (like a microwave) for one hour.
›What's a BTU?
A British Thermal Unit is the energy needed to heat one pound of water by 1 °F — about 1,055 joules. Used widely in HVAC and heating ratings.
›Is the converter free?
Yes — free, no signup, runs in your browser.
›How precise are the conversions?
Double-precision floats — accurate to 15 significant digits, well past anything you'll need in practice.