Too Drunk to Drive? Blood Alcohol Concentration (BAC) Calculator

The following tool is designed to give a ROUGH ESTIMATE of an individual’s Blood Alcohol Concentration (BAC) level. This tool should not be used to determine whether you are too drunk to drive. There are some important things to understand about BAC predictions and the decision to drive, including:

• In Washington there is NO “LEGAL LIMIT!”. 0.08% is the limit at which an adult is “per se” too impaired to drive (0.02% for minors). You can be charged with a DUI if your BAC is less than .08%. The only difference is the prosecutor will have to prove you were actually affected by alcohol. About 10% of the DUI cases I see are under 0.08%




• Everyone handles alcohol differently. Tables such as the one below use averages. Every person absorbs and dissipates alcohol at different rates. How much a person has had to eat, illness, exercise and other factors can effect your actual BAC as well. Some people feel “buzzed” at 0.08%, while others feel little effect at all.




• Breath Testing Devices are notoriously inaccurate. How hard or long you blow, your body/breath temperature, and alcohol molecules in your mouth or the ambient air, will affect the results of any given test. There can be a 20% variance due to physiological and environmental factors. Machine error is often 10% or more. In fact the machine itself will not produce an error code until the two test results from the same subject vary by almost 20%. THis means you could be well below 0.08% and still blow above the “legal limit.”

If you have already been charged with a DUI you may be discovering the estimates provided by the BAC Calculator are much different than the numbers from the police station. As mentioned above, there may be a lot of reasons for this. The Law Office of Scott Lawrence, pllc can help you understand what this means for you. Call Washington DUI attorney, Scott W. Lawrence at 425-488-8481 to schedule a free in-person DUI case consultation today!