# 일률 단위 변환기

> hp와 kW, 와트와 마력, BTU/h와 냉동톤을 변환합니다. 기계 마력(745.7 W)과 미터 마력(735.5 W)을 구분합니다.

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

Every power unit is a fixed number of watts (joules per second). Mechanical horsepower is 550 foot-pounds-force per second, which works out at exactly 745.69987158227022 W; metric horsepower (PS) is 75 kilogram-force metres per second, exactly 735.49875 W. A ton of refrigeration is 12,000 BTU/h, about 3.517 kW.

The default converts a 100 hp engine to 74.57 kW. Car specifications are the usual reason: European registration documents give engine power in kW while brochures quote PS or hp, and 100 kW is 134.1 hp or 136.0 PS.

Air-conditioner ratings in BTU/h or tons describe cooling output, not the electricity drawn: a 1.5-ton unit moves 18,000 BTU/h (5.28 kW) of heat, and its electrical input depends on its efficiency rating.

## 입력

- **값**: 변환 전 단위의 숫자 또는 단위가 붙은 숫자를 입력하세요
- **변환 전** (선택 항목: watt (W), milliwatt (mW), kilowatt (kW), megawatt (MW), gigawatt (GW), horsepower (hp), metric horsepower (PS), BTU per hour (BTU/h), ton of refrigeration (TR), kilocalorie per hour (kcal/h))
- **변환 후** (선택 항목: watt (W), milliwatt (mW), kilowatt (kW), megawatt (MW), gigawatt (GW), horsepower (hp), metric horsepower (PS), BTU per hour (BTU/h), ton of refrigeration (TR), kilocalorie per hour (kcal/h))

## 결과

- 변환된 값 — 주요 결과
- 단위 변환
- 변환 계수
- 정확성

## 공식

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

## 계산 예제

### 100 hp in kW

- 값: 100 hp
- 변환 전: horsepower (hp)
- 변환 후: kilowatt (kW)
- **변환된 값: 74.5699871582 kW**
- **정확성: 정확함**
- 검증 출처: 1 hp = 550 ft·lbf/s = 550 × 0.3048 × 4.4482216152605 W = 745.69987158227022 W (NIST SP 811 App. B)

### 1 kW in hp

- 값: 1 kW
- 변환 전: kilowatt (kW)
- 변환 후: horsepower (hp)
- **변환된 값: 1.3410220896 hp**
- 검증 출처: 1000 / 745.69987158227022 (Python 3.8 fractions from the legal definitions)

### 12,000 BTU/h is one ton of refrigeration

- 값: 12,000 BTU/h
- 변환 전: BTU per hour (BTU/h)
- 변환 후: ton of refrigeration (TR)
- **변환된 값: 1 TR**
- 검증 출처: 1 ton of refrigeration = 12,000 BTU/h (NIST SP 811 App. B)

### Zero power

- 값: 0 W
- 변환 전: watt (W)
- 변환 후: horsepower (hp)
- **변환된 값: 0 hp**
- **정확성: 정확함**
- 검증 출처: 0 × any factor = 0

### 1 metric horsepower in watts

- 값: 1 PS
- 변환 전: metric horsepower (PS)
- 변환 후: watt (W)
- **변환된 값: 735.49875 W**
- 검증 출처: 1 PS = 75 kgf·m/s = 75 × 9.80665 W = 735.49875 W

## 자주 묻는 질문

### How many watts are in a horsepower?

745.7 W for mechanical horsepower (550 ft·lbf/s), 735.5 W for metric horsepower (PS or CV), and exactly 746 W for the electric horsepower used to rate electric motors; NIST SP 811 lists all three. Mechanical and metric horsepower differ by 1.4%, enough to matter when comparing car figures.

### How do I convert kW to hp?

Multiply by 1.34102 for mechanical horsepower or by 1.35962 for metric PS. A 150 kW engine is 201.2 hp or 203.9 PS. To go from hp to kW, multiply by 0.7457, so the default 100 hp is 74.57 kW.

### What is the difference between hp, bhp and PS?

hp and bhp use the same 745.7 W unit; “brake” horsepower means the power was measured at the engine's output shaft, before transmission losses. PS (Pferdestärke) is metric horsepower, 735.5 W, also written CV or ch. A car quoted at 150 PS makes 147.9 hp or 110.3 kW.

### What does a 1.5-ton air conditioner mean?

It removes 18,000 BTU of heat per hour, which is 5.28 kW of cooling. A ton of refrigeration is 12,000 BTU/h, the rate that melts one short ton (2,000 lb) of ice in 24 hours, because ice absorbs 144 BTU per pound as it melts. The electricity it draws is lower and depends on its efficiency rating.

### How many BTU/h is 1 kW?

3,412.14 BTU/h. One watt is 3.41214 BTU/h, so a 2 kW electric heater gives out 6,824 BTU/h, and a 12,000 BTU/h air conditioner is rated at 3.517 kW of cooling. The factor is the same as between kWh and BTU because both sides are divided by one hour.

### “일률 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: 5. 예를 들어 “100 hp in kW”은 1 hp = 550 ft·lbf/s = 550 × 0.3048 × 4.4482216152605 W = 745.69987158227022 W (NIST SP 811 App. B)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)