Blood Alcohol Calculator We are all different – A BAC calculation is just an estimate. The most accurate measuring tools are a blood test or a Breathalyzer. 0.00-0.03% – No impairment, normal behavior 0.03-0.06% – Mild impairment and euphoria, diminished inhibitions 0.06-0.10% – Worsening impairment, euphoria, buzzed 0.10-0.20% – Loss of motor control Alcohol By Volume ABV or Alcohol by volume is