Watt Converter

Enter a value in watts and the Watt Converter instantly shows the equivalent in kilowatts, milliwatts, horsepower, BTU/h, megawatts, and more. Pick your input unit from the dropdown — you're not locked into starting from watts. Great for electrical, mechanical, and thermal power conversions across more than ten common power units. Also try the find EIRP with EIRP Calculator.

Enter the power value you want to convert

Results

Watts (W)

--

Kilowatts (kW)

--

Milliwatts (mW)

--

Megawatts (MW)

--

Horsepower (HP)

--

BTU per Hour (BTU/h)

--

Calories per Second (cal/s)

--

Kilojoules per Hour (kJ/h)

--

Gigawatts (GW)

--

Results Table

Frequently Asked Questions

What is a watt?

A watt (W) is the International System of Units (SI) unit of power. It represents an energy transfer rate of one joule per second (1 W = 1 J/s). Watts are used to describe how quickly a device consumes or produces energy — for example, a 60W light bulb consumes 60 joules of energy every second. See also our E = mc².

How do you convert watts to kilowatts?

To convert watts to kilowatts, divide the watt value by 1,000. For example, 1,500 watts equals 1.5 kilowatts (1,500 ÷ 1,000 = 1.5 kW). Kilowatts are commonly used for household appliances and electricity billing.

How do you convert horsepower to watts?

One mechanical horsepower (HP) equals 745.7 watts. To convert horsepower to watts, multiply the HP value by 745.7. For example, 160 HP equals 119,312 watts (160 × 745.7 = 119,312 W).

How do you convert watts to BTU per hour?

One watt equals approximately 3.41214 BTU per hour (BTU/h). To convert watts to BTU/h, multiply the watt value by 3.41214. Conversely, divide BTU/h by 3.41214 to get watts. This conversion is commonly used in heating, ventilation, and air conditioning (HVAC) systems. You might also find our Bullet Energy Calculator useful.

What is the difference between watts and watt-hours?

Watts (W) measure power — the rate at which energy is used or produced at any given moment. Watt-hours (Wh) measure energy — the total amount of power consumed over a period of time. A 100W device running for 10 hours consumes 1,000 Wh (1 kWh) of energy. Power and energy are related but distinct quantities.

How many milliwatts are in one watt?

There are 1,000 milliwatts (mW) in one watt. Milliwatts are used for very small power values such as those found in radio signals, audio equipment, and low-power electronics. To convert watts to milliwatts, simply multiply by 1,000.

What is 0.5 mW in watts?

0.5 milliwatts equals 0.0005 watts. To convert milliwatts to watts, divide by 1,000. Milliwatt values are typical in telecommunications and wireless signal strength measurements.

What are some common power unit conversions to know?

Key power conversions include: 1 kW = 1,000 W, 1 MW = 1,000,000 W, 1 HP = 745.7 W, 1 W = 3.41214 BTU/h, and 1 W = 0.239006 calories per second. These conversions are frequently used in electrical engineering, mechanical engineering, and energy management.