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dBm to Watt Calculator

Convert RF power between dBm, watts, milliwatts and dBW.

RF Power Conversion
dBm
⇄
Watts / mW
STEP 1

What do you want to calculate?

dBm → Watt Convert RF power from dBm to watts
Linear Power → dBm Convert power from watts/mW to dBm
dBm → mW Convert dBm to milliwatts
dBm / Watt → dBW Convert power to decibel-watts (dBW)
STEP 2

Enter the value

dBm
0 dBm = 1 mW. Standard values range from -120 dBm (RX sensitivity) to +40 dBm (high power).
Result

What is dBm?

dBm is a logarithmic power ratio unit referenced to 1 milliwatt (mW). It is the industry standard for expressing RF signal levels, wireless link budgets, transmit powers, and receiver sensitivities.

dBm to Watt Formula

P(W) = 10(P(dBm) / 10) × 0.001 = 10((P(dBm) - 30) / 10)

Watt to dBm Formula

P(dBm) = 10 × log₁₀(P(W) / 0.001) = 10 × log₁₀(P(W)) + 30

dBW Relationship

P(dBW) = P(dBm) - 30

Common RF Power Reference Table

dBm mW Watts Common Typical Application
-100 dBm 0.0000001 mW 0.1 pW Wi-Fi / BLE minimum receiver sensitivity
-30 dBm 0.001 mW 1 µW Strong received signal indicator (RSSI)
0 dBm 1 mW 0.001 W Standard 1 mW reference point (BLE default TX)
14 dBm 25 mW 0.025 W LoRa / Sub-1GHz standard transmit power (EU)
20 dBm 100 mW 0.1 W Standard Wi-Fi 2.4 GHz max EIRP (ETSI)
30 dBm 1,000 mW 1 W 1 Watt RF Power Amplifier
33 dBm 2,000 mW 2 W GSM 900 MHz mobile phone burst transmit power
40 dBm 10,000 mW 10 W Cellular small cell base station transmitter

Where dBm is Used

  • RF Transceivers (e.g., CC1101, SX1276, ESP32 Wi-Fi/BLE)
  • Antenna link budget calculations and path loss modeling
  • Spectrum analyzers and RF power meters
  • Low Noise Amplifiers (LNA) and Power Amplifiers (PA)