How do I convert electric horsepower to watts?

Formula : W = hp(E) × 746 Examples : 1 hp(E) = 746 W 5 hp(E) = 3,730 W = 3.73 kW 10 hp(E) = 7,460 W = 7.46 kW 0.5 hp(E) = 373 W Electric HP to Watts converter →

What is the difference between electric and mechanical horsepower?

Electric HP (hp(E)) : 746 W exactly (US electric motors) Mechanical HP (hp) : 745.7 W (550 ft⋅lb/s, automotive standard) Difference : 0.04% (practically identical) Usage : Electric motors → hp(E) Engines (gas, diesel) → mechanical hp International → kW preferred Conversion : 1 hp(E) = 1.0004 hp (mechanical)

How much power does a 1 hp electric motor use?

Full load : 746 W input (if 100% efficient) Realistic power draw (accounting for efficiency): 50% efficiency : 1,492 W (1.5 kW) 70% efficiency : 1,066 W (1.07 kW) 85% efficiency : 878 W (0.88 kW) 90% efficiency : 829 W (0.83 kW) Example : 1 hp motor at 85% efficiency draws 878W. Running 8 hours = 7 kWh energy consumed. Modern motors: 85-95% efficient. Older motors: 70-85%.

Why use hp(E) instead of kW?

US tradition : Motor industry established before SI metric adoption Current practice : US : Both hp(E) and kW used (hp(E) more common for small motors) Europe/Asia : Primarily kW International standards : Moving toward kW only Nameplate labeling : Many US motors show both (e.g., "1 hp / 0.75 kW") Conversion : Divide hp(E) by 1.341 to get kW

How do I size a motor for my application?

Basic formula : Required hp = (Torque × RPM) ÷ 5,252 Practical approach : Determine load requirements (torque, speed, duty cycle) Add safety factor : Multiply by 1.15-1.25 (15-25% margin) Select next standard size : 1/4, 1/3, 1/2, 3/4, 1, 1.5, 2, 3, 5, 7.5, 10 hp Example : Application needs 0.8 hp → Add 25% = 1 hp → Select 1 hp motor Avoid oversizing : Wastes energy, motors run inefficiently at low load.

Electric Horsepower (hp(E)) - Unit Information & Conversion

Symbol:hp(E)

Plural:hp(E)

Category:Power

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What is a Electric Horsepower?

Electric horsepower (hp(E)) equals exactly 746 watts, standardized for electric motor ratings. 1 hp(E) = 746 W = 0.746 kW. Slightly higher than mechanical hp (745.7 W). Used in US electrical engineering and motor specifications.

History of the Electric Horsepower

Defined in early 1900s to standardize electric motor ratings. Set at exactly 746 W (rounded from mechanical hp) for simplicity in electrical calculations. Still used in US motor industry alongside kW ratings.

Quick Answer

What is Electric Horsepower? Electric horsepower (hp(E)) = 746 watts exactly. Used for electric motor ratings in the US. 1 hp(E) motor draws ~746W under full load. Slightly higher than mechanical hp (745.7 W). 10 hp electric motor = 7.46 kW. Use our power converter for conversions.

Definition

1 hp(E) = 746 W = 0.746 kW = 1.0004 hp (mechanical) = 2,545 BTU/h

Difference from mechanical hp: 746 W vs 745.7 W (0.04% higher)

Common Uses

Electric Motors: Industrial motors, pumps, compressors (ratings in hp(E)). HVAC: Fan motors, blower motors (fractional to 10 hp). Manufacturing: Conveyor motors, machine tools (1-100 hp). Residential: Garage door openers, pool pumps (0.5-3 hp).

Real-World Examples

Residential Electric Motors

Garage door opener: 0.5-1 hp(E) (373-746 W)
Pool pump: 0.75-2 hp(E) (560-1,492 W)
Well pump: 0.5-1.5 hp(E) (373-1,119 W)
Shop vacuum: 1-2 hp(E) (746-1,492 W)
Table saw: 1-3 hp(E) (746-2,238 W)
Air compressor: 1.5-5 hp(E) (1,119-3,730 W)

HVAC Motors

Furnace blower: 0.33-1 hp(E) (246-746 W)
AC fan motor: 0.25-0.75 hp(E) (187-560 W)
Commercial HVAC: 3-20 hp(E) (2,238-14,920 W)
Exhaust fan: 0.5-5 hp(E) (373-3,730 W)

Industrial Motors

Small conveyor: 1-5 hp(E) (746-3,730 W)
Pump motor: 5-50 hp(E) (3,730-37,300 W)
Air compressor: 5-100 hp(E) (3,730-74,600 W)
Machine tool: 3-25 hp(E) (2,238-18,650 W)
Industrial fan: 10-100 hp(E) (7,460-74,600 W)

Fractional Horsepower

1/6 hp: 124 W (ceiling fan)
1/4 hp: 187 W (small blower)
1/3 hp: 249 W (furnace blower)
1/2 hp: 373 W (sump pump, opener)
3/4 hp: 560 W (larger pump)

Electric Horsepower Conversion Formulas

To Watt:

1 hp(E) = 746 W

Example: 5 hp(E) = 3730 watts

To Milliwatt:

1 hp(E) = 746000 mW

Example: 5 hp(E) = 3730000 milliwatts

To Kilowatt:

1 hp(E) = 0.746 kW

Example: 5 hp(E) = 3.73 kilowatts

To Megawatt:

1 hp(E) = 0.000746 MW

Example: 5 hp(E) = 0.00373 megawatts

To Gigawatt:

1 hp(E) = 7.4600e-7 GW

Example: 5 hp(E) = 0.000004 gigawatts

To Horsepower:

1 hp(E) = 1.000402 hp

Example: 5 hp(E) = 5.002012 horsepower

To Metric Horsepower:

1 hp(E) = 1.014278 PS

Example: 5 hp(E) = 5.071389 PS

To BTU per Hour:

1 hp(E) = 2545.457658 BTU/h

Example: 5 hp(E) = 12727.288292 BTU/h

To BTU per Minute:

1 hp(E) = 42.424294 BTU/min

Example: 5 hp(E) = 212.121472 BTU/min

To BTU per Second:

1 hp(E) = 0.707072 BTU/s

Example: 5 hp(E) = 3.535358 BTU/s

To Foot-pound per Second:

1 hp(E) = 550.221363 ft⋅lb/s

Example: 5 hp(E) = 2751.106817 ft⋅lb/s

To Foot-pound per Minute:

1 hp(E) = 33013.281802 ft⋅lb/min

Example: 5 hp(E) = 165066.409008 ft⋅lb/min

To Calorie per Second:

1 hp(E) = 178.298279 cal/s

Example: 5 hp(E) = 891.491396 cal/s

To Kilocalorie per Hour:

1 hp(E) = 641.873805 kcal/h

Example: 5 hp(E) = 3209.369025 kcal/h

To Ton of Refrigeration:

1 hp(E) = 0.212121 TR

Example: 5 hp(E) = 1.060607 TR

To Erg per Second:

1 hp(E) = 7460000000 erg/s

Example: 5 hp(E) = 37300000000 erg/s

To Joule per Second:

1 hp(E) = 746 J/s

Example: 5 hp(E) = 3730 J/s

Frequently Asked Questions

Formula: W = hp(E) × 746 Examples:

1 hp(E) = 746 W
5 hp(E) = 3,730 W = 3.73 kW
10 hp(E) = 7,460 W = 7.46 kW
0.5 hp(E) = 373 W Electric HP to Watts converter →

Convert Electric Horsepower

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Electric Horsepower Quick Info

hp(E)

Symbol:hp(E)

Category:Power

System:Various

Convert Electric Horsepower

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Electric Horsepower (hp(E)) - Unit Information & Conversion

🔄 Quick Convert Electric Horsepower

What is a Electric Horsepower?

History of the Electric Horsepower

Quick Answer

Definition

Common Uses

Real-World Examples

Residential Electric Motors

HVAC Motors

Industrial Motors

Fractional Horsepower

Electric Horsepower Conversion Formulas

Frequently Asked Questions

How do I convert electric horsepower to watts?

What is the difference between electric and mechanical horsepower?

How much power does a 1 hp electric motor use?

Why use hp(E) instead of kW?

How do I size a motor for my application?

Convert Electric Horsepower

Electric Horsepower Quick Info

Related Power Units

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