dBm to Watt Converter | RF Power Conversion Online
Convert between dBm and Watts (mW, µW, dBW) instantly. Includes common RF power reference table for antennas, WiFi, cellular, and Bluetooth.
Common RF Power Reference Values
| Device / Standard | Typical Power |
|---|---|
| GPS received signal | -130 dBm / 0.1 fW |
| Bluetooth 4.0 Class 2 Tx | +4 dBm / 2.5 mW |
| WiFi 802.11n (max) | +20 dBm / 100 mW |
| LTE/4G phone max | +23 dBm / 200 mW |
| WiFi 5G AP typical | +23 dBm / 200 mW |
| FM broadcast transmitter | +67–80 dBm / 5–10 kW |
How to Use
- To convert from dBm to Watts: enter a dBm value and click 'Convert'.
- To convert from Watts to dBm: switch to 'Watt → dBm' mode, enter the power in watts (or mW), and click 'Convert'.
- Results show the equivalent value in dBm, dBW, W, mW, and µW simultaneously.
- Formula: P(W) = 10^(dBm/10) / 1000; P(dBm) = 10 × log10(P(mW)).
- Consult the reference table for typical power levels of common RF devices.
- dBm = 0 means 1 milliwatt of power.
About dBm and RF Power
What is dBm?
dBm (decibels relative to one milliwatt) is a logarithmic unit of power used extensively in RF engineering, telecommunications, and audio. The formula is: P(dBm) = 10 × log₁₀(P(mW)). Key values: 0 dBm = 1 mW, +10 dBm = 10 mW, +20 dBm = 100 mW, +30 dBm = 1 W, −10 dBm = 0.1 mW, −30 dBm = 1 µW. The logarithmic scale makes it easy to handle the enormous power range from picoWatts to kiloWatts.
dBm vs dBW
dBm is referenced to 1 milliwatt; dBW is referenced to 1 watt. The relationship is: dBW = dBm − 30. So 30 dBm = 0 dBW = 1 watt. dBW is more common in satellite and high-power applications; dBm is used for everything from received signal strengths (−100 dBm for weak cellular signals) to transmitter outputs (+43 dBm for 20W base stations). Both use logarithmic math, so power levels add (in dB) rather than multiply.
Typical RF Power Levels
Common RF power reference levels: Bluetooth (BT 4.0 Class 2) = +4 dBm (2.5 mW), WiFi 802.11n (max) = +20 dBm (100 mW), LTE/4G mobile phone max = +23 dBm (200 mW), 2.4GHz WiFi AP typical = +15 to +20 dBm, microwave oven leakage limit = −22 dBm/cm², FM broadcast transmitter = +67 to +80 dBm (5–10 kW), GPS received signal = −130 dBm. Receiving systems must handle from −120 dBm (noise floor) to +30 dBm (strong signal).
Link Budget Calculations
In RF system design, link budget = Transmit Power (dBm) + Transmit Gain (dBi) − Free Space Path Loss (dB) + Receive Gain (dBi) − Receive System Noise (dB) ≥ Required SNR (dB). Using dBm throughout makes link budget calculation a simple addition and subtraction problem. For example: 23 dBm Tx + 5 dBi antenna − 80 dB path loss + 3 dBi receive antenna = −49 dBm received. This received power must exceed the receiver sensitivity (e.g. −100 dBm for 4G).
Key Features
- Bidirectional conversion: dBm ↔ W with full unit display
- Shows dBm, dBW, W, mW, and µW simultaneously
- Reference table of common RF power levels
- Handles power range from µW (−90 dBm) to kW (+90 dBm)
Common Applications
- RF link budget calculation for wireless systems
- Antenna and transmitter power analysis
- WiFi, Bluetooth, and cellular signal strength interpretation
- Radar and satellite communication system design
- Audio engineering signal level conversion