E
EMC
RF Power

dBm to mW Calculator

Instantly convert Decibel Milliwatt (dBm) to Milliwatt (mW). Dual-interactive inputs with standard formulas.

dBm
mW

Conversion Theory & Math Derivation

Mathematical Formulas:

dBm to mW: mW = 10^(dBm / 10)
mW to dBm: dBm = 10 * log10(mW)

Step-by-Step Derivation & Logic:

  1. dBm (decibel-milliwatt) is an absolute logarithmic unit of power, referenced to 1 milliwatt (mW).
  2. The formula to convert linear milliwatts (mW) to decibel-milliwatts (dBm) is: P(dBm) = 10 * log10(P(mW)).
  3. To go from dBm back to milliwatts, we apply the inverse logarithm: P(mW) = 10^(P(dBm) / 10).

Note: Decibel calculations represent power or voltage logarithmic ratios. In RF systems, power and voltage conversion requires a clear load resistance context (typically 50 Ohms in standard laboratory setups). Incorrect impedance assumptions will lead to 30-40dB errors in readings.

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