Calculate your BAC – your Blood Alcohol Concentration
Use one or both of the methods below to calculate your BAC. This will give you a rough estimate of what your blood alcohol level may have been at the time of your DUI arrest. This can give you an idea of how accurate the handheld breath device was which was used during your arrest. Sometimes the police officer will have told you what your breath machine results were, sometimes not.
Blood results can take a few weeks get the results. Your police report is the best source to get your BAC results.
Method 1: Use a Chart
Use the following DUI chart from the California DMV for a rough estimate (from the DMV’s California Driver Handbook – Alcohol and Drugs):
Blood Alcohol Content Chart from DMV
Method 2: Use an online BAC Calculator
– for rough estimates of your blood alcohol content –
Calculate your BAC
The Drink Wheel is an online breath-alcohol concentration calculator from Alcopro, a supplier of drug and alcohol testing products. The Drink Wheel will calculate a rough estimate of the concentration of Alcohol in your blood based on how much you have been drinking.
These rough estimates of BAC are for an average healthy person and assume typical beverage sizes, recipes and alcohol content.
DUI Law in California
In California, it is illegal for any person to operate:
- A motor vehicle with a BAC of 0.08% or higher.
- Any vehicle requiring a commercial driver license (with or without a commercial driver license issued to the driver), with a BAC of 0.04% or higher.
- A motor vehicle with a BAC of 0.01% or higher, if the person is under age 21.
- A motor vehicle with a BAC of 0.01% or higher at any age if the person is on DUI probation.
What’s the difference between the breath machine I blew into at the side of the road and the breath machine I blew into at the police station?
Preliminary Alcohol Screen device (PAS device)
Usually after you have done some field sobriety tests after you got pulled over, the officer will bring out a handheld breath device that he will get you to blow into. This handheld breath machine is called a preliminary alcohol screening device (PAS device for short). Under the law it is described as a field sobriety test which the officer can use to detect the presence of alcohol in you.
Under the law, blowing into this device is supposed to be optional; the officer must tell you that you can refuse this test, unfortunately officers usually never tell you it is optional to blow into this device and they will make you blow into it. After you blow into it; they almost always will not tell you your results.
Breath machines at the police station
The results of the PAS device at the scene of your arrest are not as accurate as the breath machines at the police station that you might have blown into. Prosecutors give more weight to the breath results from the machines at the police stations. However, if the breath results from the PAS device are lower than your breath results from the machine at the police station, you can argue that your blood alcohol rose after driving and you potentially have a rising blood alcohol defense, especially if your results are near .08.
Yes, your blood alcohol level may be under the .08 limit, but the police can still charge you with a DUI if the arresting police officer believed your driving was impaired due to your consumption of alcohol or drugs. This is according to:-
California Vehicle Code VC 23152(a)
(a) It is unlawful for any person who is under the influence of any alcoholic beverage or drug, or under the combined influence of any alcoholic beverage and drug, to drive a vehicle.
The DUI law in California has 2 parts:-
VC 23152(b) Driving with a level of .08 or higher –
If you take a blood or breath test and your result is .08 or higher you will be charged with violating this DUI law.
VC 23152(a) This part of the DUI law in California states that you are not allowed to drive under the influence of alcohol or drug or both.
Under the limit DUI
This is an opinion crime which means if the officer thinks in his opinion that you are under the influence of alcohol or a drug he can arrest you for a DUI in accordance with VC 23152(a). This law gives the officer the power to arrest you even if you have a breath or blood result under .08. If the officer feels you have been drinking and driving and he believes you are under the influence he can arrest you for a DUI. The officer will usually consider the following to form his opinion:
- Your driving
- Your physical symptoms (speech, eyes, breath, etc.)
- And your performance on the Field Sobriety tests
Definition of Driving Under the Influence
A person is considered under the influence of an alcoholic beverage, drug, or combination of alcohol and drugs when his/her physical or mental abilities are impaired to such a degree that he/she no longer has the ability to drive a vehicle with the caution characteristic of a sober person of ordinary prudence, under the same or similar circumstances.
VC 23152(a)
If you blow a breath result under .08 you can still be charged with a DUI if the officer believes in his opinion you are under the influence of alcohol i.e. you are impaired by alcohol as this law allows people to be charged with a DUI even if they have a breath result under .08 such as .07 or .06.
If you refuse to take a breath or blood test you can still be charged with a DUI under this law (VC 23152(a)) if the officer believes in his opinion you are under the influence of alcohol and impaired.
If the officer suspects you have consumed a drug (the drug can be legal or illegal) and the drug has affected your ability to drive you can be charged with a DUI under this law (VC 23152(a)) if the officer believes in his opinion you are under the influence of a drug and impaired.
In summary, this law has given the police a lot of power as they can arrest and have someone charged with a DUI based simply on their opinion. If the officer thinks in his opinion you are under the influence of alcohol or a drug you can be charged with a DUI even if your breath or blood result is under .08 and you can be charged with a DUI even if you refused to take a breath or blood test.
