dBm ↔ dBµV Converter (with Impedance)
Convert between dBm and dBµV for a given impedance. At 50 Ω, dBµV = dBm + 107.
Worked example
(Impedance 50 Ω) Power level -20 dBm, Voltage level 86.9897 dBµV
Formula
dBµV = dBm + 90 + 10·log₁₀(Z)
At 50 Ω: dBµV = dBm + 107
How it works
Spectrum analyzers often display dBm, while EMI receivers and standard limits use dBµV. The two are linked by the system impedance Z: dBµV = dBm + 90 + 10·log₁₀(Z). For a 50 Ω system, simply add 107.
Practical tipIn 75 Ω systems (broadcast, CATV) the offset is about 108.75, so using the 50 Ω constant introduces a 1.76 dB error. Check the impedance first.
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Results and summaries are for reference. For certification and test reports use the latest official standard text and calibrated instrument data. Last updated: 2026-10-10