Convert Watts to Horsepower

To convert watts (W) to horsepower (hp), use the right conversion factor and a simple formula.

• Mechanical horsepower (hp) (common in the U.S. for motors):
  hp = watts ÷ 745.7

• Metric horsepower (PS) (common in some car specs):
  PS = watts ÷ 735.5

Steps:

1. Pick the horsepower type you need (hp or PS).
2. Divide the watt value by the matching number.

Example (mechanical hp):

• 5300 W ÷ 745.7 = 7.1074 hp

Tip: If you’re converting motor power, the label often lists watts or kW. Convert kW to W first by using 1 kW = 1000 W.

How do you convert watts to horsepower?

To convert watts (W) to horsepower (hp), divide watts by 746.
Formula: hp = W ÷ 746
Example: 1,492 W ÷ 746 = 2 hp.

How many watts are in 1 horsepower?

1 horsepower equals about 746 watts.
This value is for mechanical horsepower, which is the most common type.

What’s the difference between mechanical horsepower and metric horsepower?

Mechanical horsepower (US/UK) is 745.7 W (often rounded to 746 W).
Metric horsepower (PS) is 735.5 W.
If you use the wrong type, your result will be off by about 1 to 2 percent.

Which horsepower unit should I use for motors and engines?

In many specs for motors and engines, mechanical horsepower is used.
In some countries and older vehicle specs, metric horsepower (PS) appears.
Always match the horsepower type shown on the nameplate or manual.

How do you convert horsepower to watts?

Multiply horsepower by 746 to get watts.
Formula: W = hp × 746
Example: 5 hp × 746 = 3,730 W.

Can I convert watts to horsepower using kilowatts?

Yes. Convert kilowatts (kW) to horsepower by multiplying by 1.341.
Formula: hp = kW × 1.341
Example: 2 kW × 1.341 = 2.682 hp.

Why does my watt-to-horsepower result not match a motor’s rated horsepower?

Rated horsepower often refers to shaft output, while watts may describe electrical input.
Motors lose power to heat and friction, so output is lower than input.
Efficiency and power factor (for AC motors) can change the numbers a lot.

Does watts-to-horsepower conversion change for electric vs gas engines?

The math conversion stays the same because watts and horsepower measure power.
What changes is how power is measured and reported. Electric motors may list input watts, while engines often list output horsepower.

Is horsepower the same as torque?

No. Horsepower and torque are linked, but they aren’t the same.
Torque is a twisting force. Horsepower is how fast work gets done.
For rotating systems: hp = (torque in lb-ft × RPM) ÷ 5252.

How accurate is using 746 watts per horsepower?

It’s accurate for mechanical horsepower and good for most everyday needs.
For precise work, use 745.699871582 W per hp.
Small rounding changes matter more at high power levels.

How do I convert watts to horsepower for a 3-phase motor?

You can convert watts to horsepower the same way: hp = W ÷ 746.
If you start with volts and amps, real input power depends on power factor and efficiency.
Many 3-phase motor labels list kW, hp, amps, and efficiency to help you compare.

What horsepower is 1000 watts?

1000 W ÷ 746 = 1.34 hp (rounded).
So 1000 watts is about one and one-third horsepower.

What horsepower is 2000 watts?

2000 W ÷ 746 = 2.68 hp (rounded).
This is mechanical horsepower, using the common 746 W per hp value.

What’s the easiest way to estimate watts to horsepower in your head?

Use 750 W as a quick estimate for 1 hp.
Then divide watts by 750 for a close answer.
Example: 1500 W ÷ 750 ≈ 2 hp.