Horsepower to Watt Converter
Enter the value that you want to convert horsepower (hp) to watt (W) or watt to horsepower.Also written as HP to W conversion.
1 horsepower = 746.0430000 watt
Formula: watt = horsepower value × 746.0430000
HP to W — horsepower to watt
10 horsepower = 7460.43000 watt
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How Horsepower Relates to Watt
The Horsepower in Engineering
Horsepower (hp) is a unit of power measurement. 1 horsepower is equal to 746.0430000 watt.
About the Watt
Watt (W) is a unit of power measurement. 1 watt is equal to 0.0013404 horsepower.
Power Measurement Across Applications
Power units span from milliwatts in electronics to megawatts in power plants. Engine output is still quoted in horsepower (mechanical, metric, and electrical — all slightly different). HVAC systems rate cooling in tons of refrigeration or BTU/hour. Solar panels specify watts peak. Electric motors list watts or kilowatts. Each industry carries its historical unit preferences, making conversion between them a daily necessity.
horsepower to watt metric conversion table
| 0.01 hp | = | 7.46043 W |
| 0.1 hp | = | 74.60430 W |
| 1 hp | = | 746.04300 W |
| 2 hp | = | 1492.08600 W |
| 3 hp | = | 2238.12900 W |
| 4 hp | = | 2984.17200 W |
| 5 hp | = | 3730.21500 W |
| 6 hp | = | 4476.25800 W |
| 7 hp | = | 5222.30100 W |
| 8 hp | = | 5968.34400 W |
| 9 hp | = | 6714.38700 W |
| 10 hp | = | 7460.43000 W |
| 11 hp | = | 8206.47300 W |
| 12 hp | = | 8952.51600 W |
| 13 hp | = | 9698.55900 W |
| 14 hp | = | 10444.60200 W |
| 15 hp | = | 11190.64500 W |
| 16 hp | = | 11936.68800 W |
| 17 hp | = | 12682.73100 W |
| 18 hp | = | 13428.77400 W |
| 19 hp | = | 14174.81700 W |
| 20 hp | = | 14920.86000 W |
| 30 hp | = | 22381.29000 W |
| 40 hp | = | 29841.72000 W |
| 50 hp | = | 37302.15000 W |
| 60 hp | = | 44762.58000 W |
| 70 hp | = | 52223.01000 W |
| 80 hp | = | 59683.44000 W |
| 90 hp | = | 67143.87000 W |
| 100 hp | = | 74604.30000 W |
| 200 hp | = | 149208.60000 W |
| 300 hp | = | 223812.90000 W |
| 400 hp | = | 298417.20000 W |
| 500 hp | = | 373021.50000 W |
| 600 hp | = | 447625.80000 W |
| 700 hp | = | 522230.10000 W |
| 800 hp | = | 596834.40000 W |
| 900 hp | = | 671438.70000 W |
| 1000 hp | = | 746043.00000 W |
How to Convert HP to W (Horsepower to Watt)?
We can convert horsepower to watt by using an example.
Example:
Convert 20 Horsepower to Watt?
We know 1 Horsepower = 746.0430000 watt; 1 Watt = 0.0013404 horsepower.
20 horsepower = ___W
20 × 746.0430000 = 14920.86000 W (we know 1 horsepower = 746.0430000 watt)
Answer:
20 horsepower = 14920.86000 watt
Water Horsepower to Watts: Pump Efficiency and Hydraulic Systems
Water horsepower (WHP) measures the useful hydraulic power actually delivered to the fluid by a pump — the "output" power after all pump inefficiencies. One water horsepower equals 746.043 watts. WHP is calculated from flow rate and head pressure: WHP = (GPM × Head in ft × specific gravity) ÷ 3,960. Converting to watts helps compare pump output to electrical input.
- Identify the water horsepower (WHP) value.
- Multiply by 746.043 to get watts.
- For kilowatts: WHP × 0.746043.
- Note: WHP is always less than brake HP due to pump efficiency.
Water HP to Watts: Pump Output Power
Hydraulic power output of common pump applications:
| Horsepower | Watt |
|---|---|
| 0.25 WHP | 186.5 W |
| 0.5 WHP | 373 W |
| 1 WHP | 746 W |
| 2 WHP | 1,492 W |
| 5 WHP | 3,730 W |
| 10 WHP | 7,460 W |
| 50 WHP | 37,302 W |
| 100 WHP | 74,604 W |
Solved Examples: Water HP to Watts
Question 1: A well pump delivers 3 WHP of hydraulic power. Express in watts.
Solution:
Watts = WHP × 746.043
= 3 × 746.043
= 2,238.1 W
Answer: 3 WHP = 2,238.1 W of useful hydraulic power delivered to the water.
Question 2: A fire pump system must provide 25 WHP. What is that in kilowatts?
Solution:
kW = WHP × 0.746043
= 25 × 0.746043
= 18.65 kW
Answer: 25 WHP = 18.65 kW hydraulic output. The motor will need to be larger to account for pump inefficiency.
Question 3: A cooling tower pump delivers 8 WHP at 75% pump efficiency. What motor size (in watts) is needed?
Solution:
Brake HP needed = WHP ÷ efficiency = 8 ÷ 0.75 = 10.67 BHP
Motor watts = 10.67 × 746.043 = 7,958 W
WHP in watts = 8 × 746.043 = 5,968 W (useful output)
Answer: 8 WHP = 5,968 W output, but the motor must provide about 7,958 W to overcome pump losses.
Practice: Water HP to Watts
Try solving these on your own to test your understanding:
- Convert 2 WHP to watts. (Answer: 1,492.1 W)
- A pool pump delivers 1.5 WHP. Express in watts. (Answer: 1,119.1 W)
- Convert 15 WHP to watts. (Answer: 11,190.6 W)
- A sewage pump provides 7 WHP. What is that in kW? (Answer: 5.22 kW)
- A high-pressure washer pump delivers 4 WHP. Convert to watts. (Answer: 2,984.2 W)
Water HP vs. Brake HP vs. Electric HP in Pump Systems
In a pump system, power flows through three stages: Electric HP (electrical input to motor) → Brake HP (mechanical shaft output from motor, after motor efficiency losses) → Water HP (hydraulic output from pump, after pump efficiency losses). A system delivering 5 WHP with 80% pump efficiency and 90% motor efficiency needs: 5 ÷ 0.80 = 6.25 BHP shaft input, and 6.25 ÷ 0.90 = 6.94 electrical HP = 5,178 W from the grid.
Calculating Water Horsepower from Flow and Head
WHP = (Q × H × SG) ÷ 3,960, where Q = flow in US gallons per minute, H = total dynamic head in feet, SG = specific gravity (1.0 for water). Example: a pump moving 200 GPM against 100 ft of head delivers WHP = (200 × 100 × 1.0) ÷ 3,960 = 5.05 WHP = 3,768 W. This formula is fundamental to pump selection and energy cost estimation.
Key Takeaways
- 1 water HP = 746.043 watts.
- WHP measures useful hydraulic power delivered to the fluid.
- WHP is always less than brake HP (by the pump efficiency factor).
- Formula: WHP = (GPM × Head ft × SG) ÷ 3,960.
- System efficiency = motor efficiency × pump efficiency (typically 50-75% overall).
Horsepower to Watt Conversion Formula
watt = horsepower × 746.0430000
1 horsepower = 746.0430000 watt
1 watt = 0.0013404 horsepower
Reverse: horsepower = watt × 0.0013404
Frequently Asked Questions
How many watt are in 1 horsepower?
There are 746.0430000 watt in 1 horsepower. To convert horsepower to watt, multiply the value by 746.0430000.
How do I convert horsepower to watt?
Multiply your horsepower value by 746.0430000 to get the equivalent in watt. For example, 5 horsepower = 5 × 746.0430000 = 3730.21500 watt.
How do I convert watt to horsepower?
Multiply your watt value by 0.0013404 to get the equivalent in horsepower. Alternatively, divide by 746.0430000.
What is 10 horsepower in watt?
10 horsepower is equal to 7460.43000 watt.
What is 100 horsepower in watt?
100 horsepower is equal to 74604.30000 watt.