What is the difference between hp and PS?

hp (mechanical horsepower) equals 745.7 watts and originated from James Watt's measurement of horse power. PS (Pferdestärke, metric horsepower) equals 735.5 watts and is defined as lifting 75 kgf one meter in one second. PS is used in Europe and Japan, while hp is standard in the US and UK.

How to convert kW to hp?

Divide the power in kilowatts by 0.7457 to get mechanical horsepower. For example, 10 kW = 10 / 0.7457 = 13.41 hp. Alternatively, multiply kW by 1.341 to get hp.

BTU/h (British Thermal Units per hour) is a unit of power commonly used in HVAC and heating applications. 1 BTU/h = 0.000293071 kW. Air conditioners and heaters are often rated in BTU/h.

How does power relate to torque?

Power equals torque multiplied by angular velocity. In practical terms: P (kW) = T (Nm) × n (RPM) / 9549. This means the same power can be achieved with high torque at low speed or low torque at high speed.

Is electric hp different from mechanical hp?

Yes. Electric horsepower is defined as exactly 746 watts, while mechanical horsepower is 745.69987 watts. The difference is negligible (0.04%) and in practice they are used interchangeably. This calculator uses the mechanical hp value (0.7457 kW).

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功率單位轉換器

立即在所有常見工程功率單位之間進行轉換。在任何單位中輸入數值，即可同時查看所有轉換結果。

kW ↔ hp PS ↔ BTU/h Nm × RPM

功率數值

輸入單位

扭矩 (Nm)

轉速 (RPM)

快速預設

所有轉換

千瓦

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瓦特

—

機械馬力

—

公制馬力 (PS)

—

BTU 每小時

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英尺·磅力每秒

—

千卡每小時

—

Nm × RPM 等效值

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由扭矩計算功率

當已知扭矩與轉速時，功率計算如下：

P — 功率 (kW)
T — 扭矩 (Nm)
n — 轉速 (RPM)

轉換至 kW 的係數

單位	符號	× 係數 = kW	精確值
瓦特	W	÷ 1000	1 W = 0.001 kW
機械馬力	hp	× 0.7457	1 hp = 745.69987 W
公制馬力	PS	× 0.7355	1 PS = 735.49875 W
BTU 每小時	BTU/h	× 0.000293071	1 BTU/h = 0.293071 W
英尺·磅力/秒	ft·lbf/s	× 0.001355818	1 ft·lbf/s = 1.355818 W
千卡/小時	kcal/h	× 0.001163	1 kcal/h = 1.163 W

實務範例

範例 — 將 10 hp 轉換為其他單位

已知： 10 hp（機械）

kW = 10 × 0.7457 = 7.457 kW

W = 7457 W

PS = 7.457 / 0.7355 = 10.14 PS

BTU/h = 7.457 / 0.000293071 = 25,436 BTU/h

ℹ️ 注意： hp 與 PS 的差異僅約 1.4%。1 hp = 1.01387 PS。在許多實務情境中，兩者可互換使用，但進行精確的工程計算時，請使用正確的換算係數。