Matching Mixer Output to Amplifier Input

[Randy L]

I see amplifier specifications listing input sensitivites in vrms. Example is QSC amps which have a 1.2Vrms input sensitivity.
However, I see many mixer mfg's rating the output of their mixers in dBu...say 21dBu.

So is there a chart or other formula to convert the mixer's dBu rating to voltage in Vrms?

[Sydney]

http://www.sengpielaudio.com/calculator-db-volt.htm
http://www.pronine.ca/vdbudbm.htm