What is BAC?

What Is BAC, How Is It Calculated, & How Does It Relate To Pennsylvania Accidents?

What is BAC?

If you’ve ever been pulled over and suspected of drunk driving, you’ve likely had your BAC level tested before. Blood alcohol concentration or BAC, refers to the percent of alcohol in your bloodstream. BAC can range from 0.00% to 1.48% (one of the highest levels ever recorded). A BAC of 0.35% or higher will likely lead to a loss of consciousness.

Alcohol can severely impair a driver’s ability to properly operate a vehicle and can often lead to very serious accidents. In fact, there are over 200 fatal drunk driving accidents in Pennsylvania each year. According to the CDC, alcohol can start affecting your ability to drive safely with a BAC as low as 0.02%. Thus, understanding how alcohol affects your body is just as important as understanding what BAC is.

How Is BAC Calculated?

how bac is calculated

BAC is often measured using a breathalyzer. Breath analyzers do not directly measure blood alcohol content or concentration. Instead, they measure BAC indirectly by measuring the amount of alcohol in an individual’s breath. Alcohol concentration levels can also be estimated using a few variables that factor into BAC.  

Factors that affect BAC

Factors affecting bac

There are a number of factors that affect BAC, the most obvious being how much you’ve had to drink. Body weight and biological sex are also large contributing factors that play a role in BAC calculations. Most BAC charts (like the ones featured below) only take the number of standard drinks, body weight, and biological sex into account. However, only using three variables has its limitations. BAC is also affected by:

  • Food consumption
  • Age
  • Body type
  • Fat/muscle content
  • Metabolism
  • Hydration

A BAC chart is a good starting point for obtaining a rough estimate of what BAC could be given certain variables, but it should be taken with a grain of salt. There are better ways to obtain a more accurate estimate.  

BAC Chart For Men (After 4 Hours of Drinking)

The following chart can be used to estimate BAC after 4 hours of drinking. Charts are also available for 1, 2, 3, 5, and 6 hours after drinking (view all BAC tables for men).

# of Drinks / Body Weight160 lbs200 lbs240 lbs
2 drinks0.000.000.00
3 drinks0.050.000.00
4 drinks0.280.080.00
5 drinks0.510.260.11
6 drinks0.740.440.26
7 drinks0.970.620.41
8 drinks1.200.800.56
9 drinks1.430.980.71
10 drinks1.661.160.86
11 drinks1.891.341.01
12 drinks2.121.521.16
13 drinks2.351.701.31

BAC Chart For Women (After 4 Hours of Drinking)

Like the men’s chart, the women’s chart below is designed to obtain an estimate for BAC 4 hours after drinking. There are also charts available for 1, 2, 3, 5, and 6 hours after drinking (view all BAC tables for women).

# of Drinks / Body Weight120 lbs160 lbs200 lbs
2 drinks0.100.000.00
3 drinks0.470.200.02
4 drinks0.840.480.24
5 drinks1.210.760.46
6 drinks1.581.040.68
7 drinks1.951.320.90
8 drinks2.321.601.12
9 drinks2.691.881.64
10 drinks3.062.161.86
11 drinks3.432.441.78
12 drinks3.802.722.00
13 drinks4.173.002.22

Calculating Your Own BAC

Calculating your own bac

If you’re interested in obtaining a more accurate BAC reading for yourself, you can purchase a personal breathalyzer. Innovations in breathalyzer technology make them easier to use and carry than ever before. Manufacturers like FLOOME and BACtrack offer small mobile breathalyzers that pair with your smartphone. You can use a personal breathalyzer to view your BAC level, track BAC over time, and obtain an estimate for when your BAC is expected to return to 0.00%. The results from a personal breathalyzer are private and will not be shared with anyone.

A personal breathalyzer is a good tool to help you understand your own body and how it reacts to alcohol content. After continually using a breathalyzer, you’ll be able to more accurately estimate and predict your BAC levels after a certain number of drinks over specified periods of time. Nevertheless, it’s always best to err on the side of caution. If you plan on drinking outside of your home, it’s always better to arrange a ride through a designated driver or ride sharing service.

Pennsylvania BAC Laws

Pennsylvania bac laws

If Pennsylvania police suspect hat you’re driving drunk, your BAC will be tested to determine if you are driving under the influence as outlined by Pennsylvania law. The state operates with three tiers for a DUI with penalties starting at a BAC of 0.08%. The tiers are as follows:

    1. General impairment: 0.08% to 0.099%
    1. High BAC: 0.10% to 0.159%
  1. Highest BAC: 0.16% or above

The penalties will range depending on the level of impairment. If you are under 21, you can be cited for a DUI with a BAC of only 0.02%.

Penalties for Drunk Driving in Pennsylvania

Penalties for drunk driving in Pennsylvania are defined by the BAC tier system. The penalties for a DUI are outlined in the table below:

General ImpairmentHigh BACHighest BAC
1st Offense
  • 6 months of probation
  • $300 fine
  • Mandatory alcohol highway safety school
  • Alcohol and drug treatment
  • 1 year license suspension
  • 48 hours to 6 months in prison
  • $500-5,000 fine
  • Mandatory alcohol highway safety school
  • Alcohol and drug treatment
  • 1 year license suspension
  • 72 hours to 6 months in prison
  • $1,000-5,000 fine
  • Mandatory alcohol highway safety school
  • Alcohol and drug treatment
2nd Offense
  • 1 year license suspension
  • 5 days to 6 months in prison
  • $300-2,500 fine
  • Mandatory alcohol highway safety school
  • Alcohol and drug treatment
  • Ignition interlock system for 1 year
  • 1 year license suspension
  • 30 days to 6 months in prison
  • $750-$5,000 fine
  • Mandatory alcohol highway safety school
  • Alcohol and drug treatment
  • Ignition interlock system for 1 year
  • 1st degree misdemeanor charge
  • 18 month license suspension
  • 90 days to 5 years in prison
  • $1,500-10,000 fine
  • Mandatory alcohol highway safety school
  • Alcohol and drug treatment
  • Ignition interlock system for 1 year
3rd Offense
  • 2nd degree misdemeanor charge
  • 1 year license suspension
  • 10 days to 2 years in prison
  • $500-5,000 fine
  • Alcohol and drug treatment
  • Ignition interlock system for 1 year
  • 1st degree misdemeanor charge
  • 18 month license suspension
  • 90 days to 5 years in prison
  • $1,500-10,000 fine
  • Alcohol and drug treatment
  • Ignition interlock system for 1 year
  • 1st degree misdemeanor charge
  • 18 month license suspension
  • 1 to 5 years in prison
  • $2,500-10,000 fine
  • Alcohol and drug treatment
  • Ignition interlock system for 1 year

Injuries Caused By a Drunk Driver in Pennsylvania

If you or someone you love has recently been injured in a crash with a drunk driver, you may be entitled to compensation. The car accident attorneys at Solnick & Associates, LLC can investigate your case and fight on your behalf to ensure you get the justice you deserve. Depending on the circumstances of the accident, you may even be able to hold the bar or restaurant that served the driver alcohol liable under Pennsylvania’s Dram Shop Law. Fill out a contact form or call (877) 415-6495 today to receive a free case evaluation.