Horsepower to Watt Conversion Chart
| Horsepower (Mechanical) (hp) | Watt (W) | Reference Benchmark | Formula Step |
|---|---|---|---|
| 0.1 hp | 74.56999 W | Tenth Horsepower Miniature Precision Laboratory Pump Motor | 0.1 × 745.6999 = 74.56999 W |
| 0.25 hp | 186.425 W | Quarter Horsepower Domestic Kitchen Garbage Disposal Motor | 0.25 × 745.6999 = 186.425 W |
| 0.5 hp | 372.8499 W | Half Horsepower Garage Door Opener Electric Motor Tier | 0.5 × 745.6999 = 372.8499 W |
| 0.75 hp | 559.2749 W | Three-Quarter Horsepower Residential Sump Pump Motor Standard | 0.75 × 745.6999 = 559.2749 W |
| 1 hp | 745.6999 W | Exact International Definition of One Mechanical Horsepower | 1 × 745.6999 = 745.6999 W |
| 1.5 hp | 1118.55 W | One and a Half Horsepower Workshop Table Saw Induction Motor | 1.5 × 745.6999 = 1118.55 W |
| 2 hp | 1491.4 W | Two Horsepower Heavy Workshop Air Compressor Drive Motor | 2 × 745.6999 = 1491.4 W |
| 3 hp | 2237.1 W | Three Horsepower Commercial Woodworking Planer Motor | 3 × 745.6999 = 2237.1 W |
| 5 hp | 3728.499 W | Five Horsepower Commercial Swimming Pool Filtration Pump | 5 × 745.6999 = 3728.499 W |
| 7.5 hp | 5592.749 W | Seven and a Half Horsepower Industrial Hydraulic Pump Motor | 7.5 × 745.6999 = 5592.749 W |
| 10 hp | 7456.999 W | Ten Horsepower Agricultural Deep-Well Irrigation Water Pump | 10 × 745.6999 = 7456.999 W |
| 15 hp | 11185.5 W | Fifteen Horsepower Commercial HVAC Building Chiller Motor | 15 × 745.6999 = 11185.5 W |
| 20 hp | 14913.998 W | Twenty Horsepower Industrial Air Compressor Rotary Screw Motor | 20 × 745.6999 = 14913.998 W |
| 50 hp | 37284.995 W | Fifty Horsepower Industrial Factory Overhead Crane Drive | 50 × 745.6999 = 37284.995 W |
| 100 hp | 74569.99 W | One Hundred Horsepower Heavy Industrial Hydraulic Power Pack | 100 × 745.6999 = 74569.99 W |
Horsepower (Mechanical) to Watt Formula & Unit Definitions
The exact mathematical ratio equates 1 mechanical horsepower (550 ft·lbf/s) to exactly 745.69987158227022 watts (approximately 745.6999 W). To convert mechanical horsepower into electrical watts, multiply the horsepower rating by 745.6999 (or divide by 0.001341022). Conversely, to return from watts back into horsepower, divide the wattage by 745.6999 (or multiply by 0.001341022).
Quick Estimation: Multiply horsepower by 750 (or multiply by 3,000 and divide by 4). For example, 1 hp ≈ 750 W (exact: 745.7 W); 2 hp ≈ 1,500 W (exact: 1,491.4 W); 4 hp ≈ 3,000 W (exact: 2,982.8 W).
Mechanical Horsepower (hp)
Imperial Mechanical Baseline- Creator & Origin: Formulated by Scottish engineer James Watt in 1782 to quantify steam engine pumping capacity relative to pit draft ponies.
- Standard Definition: Legally defined as 550 foot-pounds force per second (550 ft·lbf/s), equal to exactly 745.69987158227022 watts.
- Everyday Focus: Electric motor nameplates, automotive brake horsepower, compressor ratings, and boat engine outputs.
Watt Standard (W)
Base SI Power Standard- Creator & Origin: Adopted by the British Association in 1882 and named in honor of James Watt for pioneer work in steam thermodynamics.
- Standard Definition: Defined in the SI system as one joule of energy dissipated per second (1 J/s or 1 V × 1 A).
- Everyday Focus: Electrical power consumption, circuit breaker branch sizing, heat dissipation, and appliance load audits.
Frequently Asked Questions
Q.How many watts are in one mechanical horsepower?
There are exactly 745.699872 watts in one mechanical horsepower (1 hp = 745.699872 W, commonly rounded to 746 W).
Q.What is the reverse conversion from watts to horsepower?
To convert back, use the Watts to Horsepower Converter where 1 W equals ~0.001341 hp.
Q.How many watts is 1/2 hp?
1/2 hp (0.5 hp) equals approximately 372.85 watts.
Q.How many watts is 5 hp?
5 hp equals approximately 3,728.5 watts (about 3.73 kW).
Q.How do you convert hp to watts in your head?
Multiply hp by 750 (e.g. 2 hp × 750 = 1,500 W, actual 1,491.4 W).