What is the difference between mechanical and metric horsepower?

Mechanical (imperial) horsepower equals 550 foot-pounds of force per second, or about 745.7 watts. Metric horsepower (PS, the figure used on most European car specs) equals 75 kilogram-force metres per second, or about 735.5 watts. They differ by roughly 1.4 percent, so a 100 PS engine is about 98.6 mechanical hp.

How many watts are in one horsepower?

One mechanical horsepower is exactly 745.6998715822702 watts (550 ft·lbf/s). One metric horsepower (PS) is exactly 735.49875 watts. This tool keeps both so you can match whichever standard your source uses.

How do I convert kilowatts to horsepower?

Multiply kilowatts by 1.34102 to get mechanical hp, or by 1.35962 to get metric hp. For example 100 kW is about 134.1 mechanical hp or 136.0 PS. Set From to kW and To to the horsepower flavour you need.

What is BTU per hour and how does it relate to watts?

BTU per hour is a rate of energy flow used for heating and air-conditioning ratings. One BTU(IT) per hour equals about 0.293071 watts, so 1 kW is about 3412.14 BTU/h. A 12,000 BTU/h air conditioner therefore draws (or moves) roughly 3.5 kW of thermal power.

Is foot-pound per second the same as a foot-pound of energy?

No. A foot-pound (ft·lb) is a unit of energy or torque; a foot-pound per second (ft·lb/s) is a rate — energy delivered each second, which is power. One ft·lb/s equals about 1.3558 watts, and 550 ft·lb/s make one mechanical horsepower.

Is my data sent anywhere?

No. Every conversion is pure arithmetic computed in your browser with fixed physical constants. Nothing is uploaded, logged or stored on a server.

Power Converter — Gera Tools

A power converter that turns any single figure into watts, kilowatts, megawatts, mechanical horsepower, metric horsepower, BTU per hour and foot-pounds per second — all at once. Power is the rate at which energy is used or produced (energy per unit time), so it shows up everywhere: a phone charger rated in watts, a kettle in kilowatts, a power station in megawatts, a car engine in horsepower, an air conditioner in BTU per hour. Because each field uses a different tradition, comparing two spec sheets usually means a conversion — and that is exactly what this tool removes.

How it works

Every unit here is anchored to the watt, the SI unit of power (one joule per second). The tool converts your input into a watt baseline and then divides that baseline by each unit’s watt value, so a single number instantly becomes the whole grid. Type any amount, pick the From unit and the To unit, and the headline result updates live; the swap button flips the two directions in one click. The reference table underneath lists your amount in every unit simultaneously, with sensible precision — grouped decimals for normal magnitudes and scientific notation only when numbers get extreme.

The constants are fixed and exact where a definition exists. Mechanical horsepower is 550 foot-pounds-force per second, which works out to 745.6998715822702 W. Metric horsepower (PS) is 75 kilogram-force metres per second, exactly 735.49875 W. BTU per hour uses the International Table BTU, giving 0.29307107 W. One foot-pound per second is 1.3558179483314004 W. Keeping both horsepower flavours matters: European car specs quote PS, while US and UK figures usually mean mechanical hp, and mixing them introduces a quiet 1.4 percent error.

Example

A 100 kW electric motor: that is 100,000 W. Divide by the mechanical-horsepower factor and you get about 134.1 hp; divide by the metric factor and you get about 136.0 PS. The same motor moves roughly 341,214 BTU/h of equivalent thermal power. Enter 100, set From to kW, and read every one of those figures off the grid without touching a calculator.

Conversion reference

From	W	kW	hp (mech)	hp (metric)	BTU/h	ft·lb/s
1 W	1	0.001	0.0013410	0.0013596	3.41214	0.737562
1 kW	1,000	1	1.34102	1.35962	3,412.14	737.562
1 MW	1,000,000	1,000	1,341.02	1,359.62	3,412,142	737,562
1 hp (mech)	745.700	0.745700	1	1.01387	2,544.43	550
1 hp (metric)	735.499	0.735499	0.986320	1	2,509.63	542.476
1 BTU/h	0.293071	0.000293	0.000393	0.000398	1	0.216158

Every figure on this page is calculated locally in your browser using these fixed constants — no numbers are uploaded or stored.