Effortlessly convert between dBm, Watts, Volts, and Amps! Just fill in any field below, and the other values will update instantly. The default calculations are based on a \(50 \, \Omega\) impedance, but you can easily adjust it by editing the impedance field.
How to Convert Between Power in dBm and mW?
dBm is a logarithmic unit of power. It expresses the power level relative to 1 mW. The formula to calculate power in dBm is:
\(P_{\text{dBm}} = 10 \cdot \log_{10} \left( \frac{P_{\text{mW}}}{1 \, \text{mW}} \right)\)
For example, 100 mW is \(10 \cdot \log_{10} \left( \frac{100 \, \text{mW}}{1 \, \text{mW}} \right) = 20 \, \text{dBm}\).
To convert from dBm back to mW, we can rearrange the formula above to solve for \(P_{\text{mW}}\). The resulting equation is:
\(P_{\text{mW}} = 10^{\frac{P_{\text{dBm}}}{10}}\)
How to Convert dBm to Voltage?
Since dBm is a measure of power, we can convert it to mW using the formulas described above. Now, the RMS voltage depends to the impedance \(Z_0\) on which this power is dissipated. The relationship between power and RMS voltage can be expressed using the following formula:
\(V_{\text{RMS}} = \sqrt{P \cdot Z_0}\)
To find the peak-to-peak voltage, simply multiply the RMS voltage by \(2\sqrt{2}\). However, note that this conversion from RMS to peak-to-peak is true only for sine-wave signal. if your signal is not pure sine-wave, ignore the peak-to-peak values in this calculator. Instead, use the appropriate formula according to your specific signal. You can read more about the relationship of RMS to amplitude in https://en.wikipedia.org/wiki/Root_mean_square.
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