📶 dBm / Watts / Volts Converter
Convert between dBm, milliwatts, watts, and RMS voltage across standard RF impedances.
Converter
From dBm
$$P_\text{mW} = 10^{\text{dBm}/10} \qquad V_\text{rms} = \sqrt{P_W \cdot Z}$$
dBm
Results
From Power
$$\text{dBm} = 10\log_{10}(P_\text{mW}) \qquad V_\text{rms} = \sqrt{P_W \cdot Z}$$
Results
From Voltage
$$P_W = \dfrac{V_\text{rms}^2}{Z} \qquad \text{dBm} = 10\log_{10}(P_\text{mW})$$
Results
Power Gain / Loss
$$P_\text{out}(\text{dBm}) = P_\text{in}(\text{dBm}) + \text{Gain}(\text{dB})$$
dBm
dB
Results
Common dBm Reference Values (50 Ω)
| dBm | Power | Vrms (50 Ω) | Typical Use |
|---|---|---|---|
| +43 dBm | 20 W | 31.6 V | Mobile base station |
| +30 dBm | 1 W | 7.07 V | Handheld radio max |
| +20 dBm | 100 mW | 2.24 V | Wi-Fi access point |
| +10 dBm | 10 mW | 707 mV | Bluetooth Class 1 |
| 0 dBm | 1 mW | 224 mV | Reference level |
| −10 dBm | 100 µW | 70.7 mV | Strong RF signal |
| −30 dBm | 1 µW | 7.07 mV | Typical received signal |
| −60 dBm | 1 nW | 224 µV | Weak signal |
| −100 dBm | 0.1 fW | 2.24 µV | Receiver noise floor |
| −174 dBm/Hz | kTB | — | Thermal noise floor (290 K) |