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Watts to Milliwatts Conversion

One watt is 1000 milliwatts, so changing watts into milliwatts means multiplying by 1000. Type the power in watts, press Convert, and read the figure in mW.

How many milliwatts are in a watt

A milliwatt is one thousandth of a watt, which gives the fixed relationship 1 W = 1000 mW. Both units measure power, so a wattage and its milliwatt figure describe exactly the same amount, just on different scales.

Because the gap between the units is exactly 1000, the conversion shifts the decimal point three places. A thousandth of a watt is 1 mW, a single watt is 1000 mW, and 100 W is 100000 mW. Going the other way, from milliwatts to watts, you divide by 1000 instead.

Watts to milliwatts formula

The power in milliwatts, P(mW), equals 1000 times the power in watts, P(W): P(mW) = 1000 × P(W). Whatever number you have in watts, multiply it by 1000 and the product is the same power in milliwatts.

For example, converting 5 W gives P(mW) = 1000 × 5 W = 5000 mW.