This tool converts RMS Voltage to dBu.

In what follows we also provide an overview of what dBu and RMS voltage mean.

**Formula**

**dBu = 20*Log _{10}(V_{RMS}/0.7746) **

**Background**

**What is dBu?**

**dBu is the RMS voltage relative to 0.7746 Volt. **

1 V_{RMS} is therefore equivalent to 20*Log_{10}(1/0.7746) = 2.218 dBu

The inverse relationship or conversion from dBu to V_{RMS} is defined by the formula V_{RMS} = 10^{(dBu / 20)} x 0.7746.

**Notes: **

- dBu is different from dBV which is the RMS voltage relative to 1 Volt.
*dBV to dBm Calculator.* - dBu is also not the same as dBuV or dBµV which is the RMS voltage relative to 1 microvolt.
*dBµV to dBm Calculator.*

**Where does the number 0.7746 come from?**

It is the value of voltage that dissipates 1 milliwatt (mW) into a 600 ohm load. Reference: *Wikipedia article on dB Voltage*

**V = √(600Ω * 0.001W)** **Volt** **= 0.7746 V**

dBu was originally dBv, however it was changed to what it is today to avoid confusion with dBV. *Wikipedia Reference.*

**What is RMS Voltage?**

The Root mean square (RMS) voltage is the square root of the arithmetic mean of the squares of a set of voltage values.

**RMS Value Formula**

The formula for this is

**V _{RMS} = √(1/n)(V_{1}^{2} + V_{2}^{2} + … + V_{n}^{2})**

where **V _{RMS}** is the RMS value of the sequence of numbers

**V**.

_{1}, V_{2}… V_{n}Use the following calculators to find VRMS from