# 에너지 단위 변환기

> 줄, 칼로리, 영국 열량 단위, 전자볼트의 정확한 정의를 사용하여 kWh를 BTU로, 칼로리를 줄로, kcal를 kJ로, 섬을 kWh로 변환합니다.

직접 계산할 수 있는 페이지: https://www.calcopenly.com/ko/conversion/energy-converter
분야: 단위 변환기

Every energy unit is a fixed number of joules. A kilowatt-hour is exactly 3.6 MJ (1,000 W for 3,600 s), the thermochemical calorie is 4.184 J, and the International Table British thermal unit is 1,055.05585262 J (NIST SP 811), so each factor is a definition rather than a measurement.

The default converts 1 kWh to 3,412.14 BTU, the link between electricity bills and heating or air-conditioning ratings. Food energy is the other everyday use: a food Calorie is a kilocalorie, so a 2,000 kcal day is 8,368 kJ.

Some units share a name but not a size. The International Table calorie (4.1868 J) is 0.07% larger than the thermochemical one used here, and the US therm (105,480,400 J) is defined with the 59 °F BTU, so it comes to 99,976 International Table BTU rather than 100,000.

## 입력

- **값**: 변환 전 단위의 숫자 또는 단위가 붙은 숫자를 입력하세요
- **변환 전** (선택 항목: joule (J), kilojoule (kJ), megajoule (MJ), watt-hour (Wh), kilowatt-hour (kWh), megawatt-hour (MWh), calorie (cal), kilocalorie (kcal), British thermal unit (BTU), therm (US) (thm), electronvolt (eV), erg, foot-pound (ft·lbf), tonne of oil equivalent (toe))
- **변환 후** (선택 항목: joule (J), kilojoule (kJ), megajoule (MJ), watt-hour (Wh), kilowatt-hour (kWh), megawatt-hour (MWh), calorie (cal), kilocalorie (kcal), British thermal unit (BTU), therm (US) (thm), electronvolt (eV), erg, foot-pound (ft·lbf), tonne of oil equivalent (toe))

## 결과

- 변환된 값 — 주요 결과
- 단위 변환
- 변환 계수
- 정확성

## 공식

$$
\begin{gathered} x_{\text{to}} = x_{\text{from}} \times \dfrac{f_{\text{from}}}{f_{\text{to}}} \\ f = \text{one unit expressed in } \text{J} \end{gathered}
$$

## 계산 예제

### 1 kWh in BTU

- 값: 1 kWh
- 변환 전: kilowatt-hour (kWh)
- 변환 후: British thermal unit (BTU)
- **변환된 값: 3,412.14163313 BTU**
- 검증 출처: 3,600,000 J ÷ 1055.05585262 J (International Table BTU, NIST SP 811 App. B) (Python 3.8 fractions from the legal definitions)

### 1 kcal in kJ

- 값: 1 kcal
- 변환 전: kilocalorie (kcal)
- 변환 후: kilojoule (kJ)
- **변환된 값: 4.184 kJ**
- **정확성: 정확함**
- 검증 출처: Thermochemical calorie = 4.184 J exactly (NIST SP 811 App. B)

### 1 eV in joules

- 값: 1 eV
- 변환 전: electronvolt (eV)
- 변환 후: joule (J)
- **변환된 값: 1.602176634 × 10⁻¹⁹ J**
- 검증 출처: e = 1.602176634 × 10⁻¹⁹ C exactly (SI 2019), so 1 eV = 1.602176634 × 10⁻¹⁹ J

### 1 US therm in BTU

- 값: 1 thm
- 변환 전: therm (US) (thm)
- 변환 후: British thermal unit (BTU)
- **변환된 값: 99,976.1289775 BTU**
- 검증 출처: 105,480,400 J (NIST SP 811 App. B) ÷ 1055.05585262 J (Python 3.8 fractions from the legal definitions)

## 자주 묻는 질문

### How many BTU are in a kWh?

3,412.14 BTU. A kWh is 3,600,000 J and the International Table BTU is 1,055.05585262 J, so 3,600,000 ÷ 1,055.05585262 = 3,412.1416. In the other direction 1 BTU is 0.000293071 kWh, so 100,000 BTU of heat is 29.31 kWh.

### How many joules are in a calorie?

4.184 J for the thermochemical calorie used here, or 4.1868 J for the International Table calorie; NIST SP 811 lists both. Nutrition labels count kilocalories, often printed as “Calories”, so one food Calorie is 4,184 J or 4.184 kJ. EU food labels give energy in both kJ and kcal.

### What is a unit of electricity?

One kilowatt-hour, 3.6 MJ: the energy a 1,000 W appliance uses in one hour. Electricity bills in the UK and India count “units” in kWh, so a 2 kW heater running for 3 hours uses 6 units, and a 10 W LED bulb takes 100 hours to use one.

### What is the difference between kW and kWh?

A kilowatt measures power, the rate at which energy is used; a kilowatt-hour measures the energy itself, power multiplied by time. A 3 kW kettle running for 4 minutes uses 3 × 4/60 = 0.2 kWh. Convert kW with the power converter and kWh with this one.

### How many kWh are in a therm?

29.3 kWh. The US therm is 105,480,400 J (NIST SP 811), which is 29.3001 kWh; the EU and UK therm, 100,000 International Table BTU or 105,505,585.262 J, is 29.3071 kWh. The two differ by 0.024%, so either rounds to 29.3 kWh.

### “에너지 단위 변환기”의 정확도는 어느 정도인가요?

정확도는 입력값과 계산 방법의 가정에 따라 달라집니다. 십진 연산은 유효숫자 50자리를 사용하지만, 추정값·수치해석 방법·원본 데이터의 정밀도는 더 낮을 수 있습니다. 표시값을 반올림해도 이러한 한계는 사라지지 않습니다. 독립적인 출처의 풀이와 대조한 계산 예시: 4. 예를 들어 “1 kWh in BTU”은 3,600,000 J ÷ 1055.05585262 J (International Table BTU, NIST SP 811 App. B) (Python 3.8 fractions from the legal definitions)와 대조해 확인합니다.

### 이 계산 방법의 출처는 무엇인가요?

NIST SP 811 (2008), Guide for the Use of the SI, Appendix B — conversion factors; NIST Handbook 44, Appendix C — General tables of units of measurement.

## 출처

- [NIST SP 811 (2008), Guide for the Use of the SI, Appendix B — conversion factors](https://www.nist.gov/pml/special-publication-811)
- [NIST Handbook 44, Appendix C — General tables of units of measurement](https://www.nist.gov/pml/owm/nist-handbook-44-current-edition)