dBm ↔ Watt Converter
Convert
dBm is a logarithmic scale referenced to 1 mW. The engine applies the correct log/antilog.
dBm is a logarithmic unit of power referenced to 1 milliwatt: 0 dBm = 1 mW, +30 dBm = 1 W, −30 dBm = 1 µW. The relationship is P(W) = 10^((P(dBm)−30)/10).
dBm is the standard for RF and telecom power because it turns multiplication/division (gains, losses) into addition/subtraction. Converting to watts is essential when interfacing with a power supply, a thermal budget, or a wattmeter that reads linear power.
Common applications
Reading a transmitter's output in dBm; converting a receiver's sensitivity (µW) to dBm; calculating link budget gains/losses; interfacing with a linear wattmeter.
Frequently asked questions
0 dBm = 1 milliwatt (1 mW). It's the reference point for the dBm scale.
P(W) = 10^((P(dBm)−30)/10). For example, 30 dBm = 1 W; 0 dBm = 0.001 W.
Because it's logarithmic — gains and losses become simple additions, which is convenient for RF link budgets.