Decibel-milliwatts (dBm) to Watts (W) Conversion

Decibel-milliwatts

The decibel-milliwatt (dBm) is a unit of power expressed on a logarithmic scale relative to one milliwatt (1 mW). It is defined as dBm = 10 × log₁₀(P / 1 mW), where P is power in milliwatts. Used universally in RF engineering, telecommunications, and audio systems: Wi-Fi signal strength is expressed in dBm (typical values −30 to −90 dBm); a 0 dBm signal equals 1 mW; 30 dBm equals 1 W; −10 dBm equals 0.1 mW. Note: dBm cannot be converted with a simple multiplier — it requires the logarithmic formula.

Watts

The watt (W) is the SI derived unit of power, defined as one joule per second (J/s = kg·m²·s⁻³), representing the rate of energy transfer or conversion. Named after Scottish engineer James Watt, whose steam engine improvements launched the Industrial Revolution, the watt is the coherent unit for all forms of power — mechanical, electrical, thermal, and acoustic. A human at rest produces about 80 W of thermal power; a professional cyclist sustains approximately 400 W during a race; a lightning bolt peaks at around 10¹² W for microseconds.