With no benzo tolerance, I recently eyeballed what got me to where 1.5-2mg xanax got me. While lying in bed. A 12oz 5.8(?) beer put me to sleep. That's all I can say.
Be very careful... and know the pills vary in consistency between brands. I had powder. Might add I'd been drinking most a bottle of vodka a night, with frequent 300-450mg DXM with it. If anything, take it beer by beer, AND SIP SLOW. Try and notice when you get 'wooah im really getting fucked" and stop.