dBu to dBV Converter (dBu / dBV / dBm & Volts)
This dBu to dBV converter moves between dBu, dBV, dBm and volts RMS in real time. Type a value in any field and the others update instantly. Because dBm depends on load impedance, pick the impedance used for the dBm relationship (600 Ω classic audio, 50 Ω or 75 Ω RF, or a custom value). dBu and dBV always sit a fixed 2.2185 dB apart; dBm only equals dBu at 600 Ω.
Enter Any Value
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Result
Common Level Reference
| Level | dBu | dBV | Vrms | Notes |
|---|---|---|---|---|
| 0 dBu reference | 0 dBu | −2.218 dBV | 0.7746 V | = 0 dBm into 600 Ω (historical origin of dBu) |
| 0 dBV reference | +2.218 dBu | 0 dBV | 1.0 V | 1 volt RMS reference |
| Pro line level (+4 dBu) | +4 dBu | +1.78 dBV | 1.228 V | Balanced studio / broadcast nominal level |
| Consumer line level (−10 dBV) | −7.78 dBu | −10 dBV | 0.3162 V | Unbalanced −10 dBV gear (hi-fi, consumer) |
| 0 dBm into 600 Ω | 0 dBu | −2.218 dBV | 0.7746 V | 1 mW dissipated in 600 Ω |
| 0 dBm into 50 Ω | −10.79 dBu | −13.01 dBV | 0.2236 V | 1 mW dissipated in 50 Ω (RF reference) |
The dBu and dBV columns above are fixed (impedance-independent). The dBm equivalents shown in the calculator depend on the impedance you select.
About dBu, dBV & dBm Levels
dBu and dBV are voltage decibel scales: they describe an RMS voltage relative to a fixed reference, with no impedance needed. dBV references 1 volt RMS (dBV = 20·log10(V/1)). dBu references 0.7746 volts RMS (dBu = 20·log10(V/0.7746)). That odd-looking 0.7746 V is exactly √(0.001 W × 600 Ω) — the voltage that dissipates 1 milliwatt in a 600 Ω load. Historically that is why 0 dBu was defined to equal 0 dBm into 600 Ω. Because both scales use the same 20·log10 form, the gap between them is a constant: dBu = dBV + 2.2185 dB, regardless of the signal level. To convert dBu to volts directly, reverse the log: V = 0.7746 × 10^(dBu/20); to go the other way (dBV to dBu), simply add 2.2185.
Why dBm is different (it needs an impedance)
dBm is a power unit: 0 dBm = 1 milliwatt. To turn a voltage into a power you must know the load resistance, because P = Vrms² / R. So dBm = 10·log10(P/0.001) = 20·log10(Vrms) − 10·log10(R) + 30. The same voltage produces a different dBm depending on whether it drives 600 Ω, 50 Ω, or 75 Ω. This dBm to volts calculator reverses that relationship: pick the impedance, enter a dBm figure, and get the RMS voltage directly. This makes the impedance explicit so the dBm figure is never ambiguous. The classic audio value is 600 Ω; RF systems use 50 Ω (most radio gear) or 75 Ω (video, antenna feeds).
dBm only equals dBu at 600 ohms
The convenient identity "0 dBu = 0 dBm" is true only when the impedance is 600 Ω, because 0.7746 V across 600 Ω dissipates exactly 1 mW. At any other impedance the equality breaks: 0 dBu (0.7746 V) into 50 Ω is +10.79 dBm, and into 75 Ω it is +9.03 dBm. Modern audio gear is almost always voltage-driven into high-impedance inputs (10 kΩ or more), so almost no power is actually transferred — which is exactly why pro audio uses the impedance-free dBu and dBV for level and reserves dBm for cases where real power into a known load matters.
Pro (+4 dBu) vs consumer (−10 dBV) line level
Two nominal line levels dominate audio. +4 dBu (about 1.228 V RMS) is the balanced "professional" nominal level used in studios and broadcast. −10 dBV (about 0.316 V RMS) is the unbalanced "consumer" level used in hi-fi and prosumer gear. The headline difference is about 11.78 dB, not a round 14 dB, precisely because one is referenced to dBu and the other to dBV: +4 dBu = +1.78 dBV, and +1.78 dBV − (−10 dBV) = 11.78 dB. (You will often see it rounded to "11.8 dB" or quoted as "about 12 dB.") Interfacing the two without gain staging is a common cause of either weak, noisy signals or clipping. This tool functions as both a pro audio level converter and a line level converter — useful anywhere you need to reconcile the +4 dBu professional standard with the −10 dBV consumer standard.