dBm to watts and watts to dBm power conversion calculator.

dBm (decibel-milliwatts) is a unit of power that represents the power level relative to 1 milliwatt (mW), expressed in decibels. It is commonly used in wireless communication and RF engineering to express power levels, as it simplifies handling very large or small values, especially in signal transmission and reception contexts.

  • Positive dBm values indicate power levels above 1 mW.
  • Negative dBm values signify levels below 1 mW, useful for measuring weak signals in RF engineering (e.g., signals received by a mobile phone).

How to Manually Calculate

The conversion from watts (W) to dBm relies on a logarithmic scale: dBm=10×log10​(Power in mW).

  1. Convert watts to milliwatts: Multiply the power in watts by 1,000 to get milliwatts.
  2. Apply the dBm formula: Plug this value into the formula above using a calculator.

dBm/Watts Calculator

Type in either box. Conversion is automatic and instant.