Audio & RF Decibel Voltage Solver
dBm to dBV Calculator
Convert power in decibel-milliwatts (dBm) to voltage in decibel-volts (dBV) across 50Ω, 75Ω, and 600Ω loads with RMS voltage and linear power derivations.
Ref: 1 mW
dBm
Ref: 1 Vrms
dBV
RMS Voltage (Vrms)
0.2236 V
dBu Level (0.775V)
-10.79 dBu
Linear Watts
0.0010 W
Milliwatts (mW)
1.0000 mW
Decibel Voltage Reference
dBm vs dBV vs dBu at 50 Ω and 600 Ω
| dBm Level | Linear Watts | 50 Ω dBV | 50 Ω Vrms | 600 Ω dBV | 600 Ω Vrms (dBu) |
|---|---|---|---|---|---|
| +30 dBm | 1.000 W | +16.99 dBV | 7.071 V | +27.78 dBV | 24.49 V (+30.0 dBu) |
| +20 dBm | 100.0 mW | +6.99 dBV | 2.236 V | +17.78 dBV | 7.746 V (+20.0 dBu) |
| +13.01 dBm | 20.00 mW | 0.00 dBV | 1.000 V | +10.79 dBV | 3.464 V (+13.0 dBu) |
| 0 dBm | 1.000 mW | −13.01 dBV | 223.6 mV | −2.22 dBV | 774.6 mV (0.0 dBu) |
| −10 dBm | 100.0 µW | −23.01 dBV | 70.71 mV | −12.22 dBV | 244.9 mV (−10.0 dBu) |
| −30 dBm | 1.000 µW | −43.01 dBV | 7.071 mV | −32.22 dBV | 24.49 mV (−30.0 dBu) |
Knowledge Base
Frequently Asked Questions
Common questions about RF power conversions, negative dBm, and voltage calculations.
dBm is an absolute measure of power referenced to 1 milliwatt (1 mW). dBV is an absolute measure of voltage referenced to 1 Volt RMS (1 Vrms), regardless of impedance. Converting between power (dBm) and voltage (dBV) strictly requires knowing the circuit impedance (Z₀).
In a 50 Ω system, the mathematical offset is exactly 13.01 dB: dBV = dBm − 13.01. For example, 0 dBm = −13.01 dBV (0.2236 Vrms), and +13.01 dBm = 0 dBV (1.0 Vrms).
In standard 600 Ω audio and legacy telephony systems, the offset is 2.22 dB: dBV = dBm − 2.22. At 600 Ω, 0 dBm equals 0.7746 Vrms (−2.22 dBV, also known as 0 dBu).
0 dBV is defined as exactly 1.0 Volt RMS. In a 50 Ω system, 1.0 Vrms corresponds to P = 1² / 50 = 0.020 Watts (20 mW), which equals +13.01 dBm.
Both are voltage decibels, but they use different reference voltages: dBV is referenced to 1.000 Vrms. dBu is referenced to 0.7746 Vrms (the voltage required to dissipate 1 mW in a 600 Ω load). Therefore, dBu = dBV + 2.218 dB.