While most of us know that the legal Blood Alcohol Content (BAC) limit is 0.08 percent, it can be difficult to discern when this level is surpassed — without a little help, that is.

Queue the portable breathalyzer. These small devices have infiltrated the market in recent years for their ability to allow users to self-test and track their alcohol consumption before driving.

The difficulties of determining your BAC

Studies show that alcohol skews our perspective, which can make it difficult to tell how drunk you are. One study found that, while drunk, individuals subconsciously rank their level of intoxication in relation to those around who share the same gender. This may cause someone who is surrounded by a rowdy group to believe they are soberer than they actually are.

Beer goggles,” image-distorting equipment, are oftentimes used in health and driver’s education courses to simulate the effects of drinking alcohol to underage students. While these may be somewhat helpful in replicating alcohol-related impairment, it’s unlikely that an adult remembers wearing this device or compares the short experience to their state of mind while under the influence of alcohol.

BAC calculators consider factors, such as your height, weight and gender, to determine the number of drinks you should consume each hour. The National Consumers League (NCL) establishes a rule of thumb that one drink is equal to a shot (1.5 ounces) of 80 proof liquor, 12 ounces of beer (4.5% alcohol), or 5 ounces of wine (12% alcohol). However, many factors can influence your BAC.

Portable breathalyzers can help

Keith Nothacker, founder of personal-breathalyzer company, BACtrack, has likened the inability to test your BAC level to an inability to use a speedometer while driving down a highway. “I thought it was crazy that you could get pulled over, get arrested and go to jail for a number you couldn’t test yourself,” he said.

BACtrack breathalyzers marketing uses a motto that emphasizes how the device can help drivers who have been charged with a past DUI rebuild trust and accountability with loved ones.

A series of portable breathalyzers are also available on the market that range in price from $10 up to $150. While some breathalyzers may be more accurate than others, the devices are an excellent resource to understand if you should wait to drive, drink water or call for a ride after drinking alcohol.

If you are currently facing DUI charges or believe that a breathalyzer test you were given may not have been conducted properly, talk to an attorney to discuss a defense plan. A lawyer can help you fight for the best outcome to help you get back on the road.