Blood Alcohol Level Calculator

Q: How fast does alcohol leave your system?

Your body metabolizes alcohol at approximately 0.015% BAC per hour. This rate is fairly constant regardless of weight, gender, or how much you've had. Nothing speeds up this process - coffee, cold showers, and exercise don't help.

Q: Is 0.08% BAC the legal limit everywhere?

In the United States, 0.08% BAC is the legal limit for drivers 21 and over in all 50 states. However, Utah has a 0.05% limit. Commercial drivers have a 0.04% limit, and drivers under 21 face zero-tolerance laws (typically 0.00-0.02%).

Q: What is a standard drink?

A standard drink contains about 14 grams of pure alcohol. This equals: 12 oz of beer (5% ABV), 5 oz of wine (12% ABV), or 1.5 oz of spirits (40% ABV). Many drinks contain more than one standard drink.

Q: Does food affect BAC?

Yes, significantly. Food in your stomach slows alcohol absorption. Drinking on an empty stomach can result in BAC peaking 2-3 times faster than drinking with a meal. However, food doesn't reduce total absorption—it just spreads it out over time.

Q: Can I sober up faster with coffee or a cold shower?

No. Your liver metabolizes alcohol at a constant rate (about 0.015% BAC per hour), and nothing can speed this up. Coffee may make you feel more alert, but you're still impaired. Cold showers, exercise, and other remedies don't work either. The only thing that reduces BAC is time.

Q: How long after drinking can I drive?

The safest answer is don't drive after drinking any amount. Use a Time to Sober calculator to estimate when you'll reach 0.00% BAC. Even being under the legal limit doesn't mean you're unimpaired. Studies show crash risk increases at BAC as low as 0.02%.

Q: What BAC causes impairment?

Impairment begins at very low BAC levels. At 0.02% BAC, you may feel relaxed with slight changes in mood. By 0.05%, judgment and coordination are noticeably affected. At 0.08% (the legal limit), you have significantly impaired coordination, judgment, and reaction time.

Free BAC calculator that estimates your blood alcohol content using the scientifically-validated Widmark formula. Enter your weight, gender, drinks consumed, and time elapsed to see your estimated BAC, impairment level, and time until you're sober. All calculations happen instantly in your browser—no data is stored or transmitted.

Key Takeaways

Standard drink = 14g alcohol: 12oz beer (5%), 5oz wine (12%), or 1.5oz spirits (40%)
Metabolism rate = 0.015%/hour: Constant for everyone—nothing speeds it up
Women reach higher BAC: About 24% higher than men of equal weight
Legal limit = 0.08%: But impairment begins around 0.02% BAC
This is an estimate only: Never use to decide if you're safe to drive

Units:

Estimate your current blood alcohol content. Fill in the fields below and click Calculate. All calculations use the Widmark formula and happen instantly in your browser.

Your Biological Sex

👨 Male 👩 Female

This determines how alcohol distributes in your body. Women have a higher body fat ratio, so the same drinks produce ~24% higher BAC.

Body Weight

Your current weight. Heavier people have more body water to dilute alcohol.

Number of Drinks Count standard drinks, not glasses. Use 0.5 increments for partial drinks.

🍺1 beer12 oz, 5%

🍷1 wine5 oz, 12%

🥃1 shot1.5 oz, 40%

Not sure how to count? A pint of craft beer (16 oz, 7%) = ~1.5 standard drinks. A large restaurant wine pour (8 oz) = ~1.6 drinks. A Long Island Iced Tea = 3-4 drinks. When in doubt, round up.

Drink Type Pick what you drank the most of. All options use standard serving sizes.

Time Since First Drink

hrs

min

When you started drinking, not when you stopped. Your body begins metabolizing immediately.

Estimated Blood Alcohol Content

0.000%

Minimal

Safe

Caution

Over Limit

0.00% 0.08% (Legal Limit) 0.30%+

✓ Enter your information and calculate.

Effects

Alcohol

Sober In

Legal In

Your Input Summary

Gender

Weight

Drinks

Drink Type

Time Elapsed

Metric	Your Value	Reference
Blood Alcohol Content	--	Legal limit: 0.08%
Impairment Level	--	0.05% = noticeable impairment
Total Alcohol Consumed	--	1 standard drink = 14g
Alcohol Metabolized	--	Rate: 0.015%/hour
Time to 0.08% (Legal)	--	When you're legal to drive
Time to 0.00% (Sober)	--	Completely alcohol-free
Sober By (Clock Time)	--	Approximate time

What This Means

Your results will appear here after calculation.

Safety Reminders

🚗

Don't Drive

Even below 0.08%, alcohol impairs driving. Use rideshare, taxi, or a designated driver.

⏰

Time Is the Only Cure

Coffee, food, and cold showers don't speed up metabolism. Only time works.

💧

Stay Hydrated

Drink water between alcoholic drinks to reduce dehydration effects.

🍽️

Eat Before Drinking

Food slows alcohol absorption and reduces peak BAC.

Already know your BAC? Enter it below to find out when you'll reach your target level. Use the BAC Calculator tab first if you need to estimate your current BAC.

Your Current BAC (%) Enter a BAC you calculated above, or a reading from a personal breathalyzer. Example: enter 0.08 for 0.08% BAC.

Target BAC Level Choose 0.00% to know when you'll be fully sober. Choosing 0.08% only tells you when you'd be legal, not safe.

Time Until Target BAC

-- hours

Sober by: --

Current BAC

Legal (0.08%) In

Legal By

How this works: Your body metabolizes alcohol at a constant rate of approximately 0.015% BAC per hour. Nothing speeds this up—not coffee, not food, not cold showers. Individual rates range from 0.010% to 0.020%/hour.

Quick reference table—find your weight on the left and read across to see estimated BAC for different numbers of standard drinks. Values are for men after 1 hour of metabolism. No calculation needed.

Weight	1 Drink	2 Drinks	3 Drinks	4 Drinks	5 Drinks	6 Drinks

How to read this chart:
■ Green = Safe zone (below 0.05%) ■ Yellow = Caution (0.05%-0.08%) ■ Red = Over legal limit (above 0.08%)

For women: Multiply these values by approximately 1.24 (add ~24%). For example, if the chart shows 0.06% for a man, a woman of the same weight would be closer to 0.074%.

Planning ahead? This reverse calculator tells you how many drinks it would take to reach a specific BAC level. Useful for understanding your limits before going out.

Your Biological Sex

👨 Male 👩 Female

Body Weight

Your current body weight

Target BAC (%) The BAC level you want to calculate for. 0.08 = legal limit, 0.05 = noticeable impairment.

Drinking Period (hours) How long will you be drinking? Example: a 3-hour dinner party or a 4-hour barbecue.

Standard Drinks to Reach Target

To reach 0.08% BAC

Total Alcohol

Beers (12oz)

Wine (5oz)

Shots (1.5oz)

Important: This shows the amount to reach exactly the target—not to stay safely below it. For a margin of safety, plan for 1-2 fewer drinks than calculated.

How to Use This Calculator

This BAC calculator includes four specialized tools. Here's how to get accurate results from each one:

BAC Calculator Tab

The main calculator estimates your current blood alcohol content based on what you've consumed.

Select your gender — This determines the Widmark factor (r): 0.68 for men, 0.55 for women. Women typically have higher BAC due to body composition differences.
Enter your body weight — Use your actual weight, not your goal weight. You can switch between pounds (lbs) and kilograms (kg).
Enter number of drinks — Count standard drinks, not glasses. A large craft beer or generous wine pour may count as 1.5-2 drinks. You can enter half drinks (1.5, 2.5, etc.).
Select drink type — Choose what you're drinking. Beer (12oz, 5%), wine (5oz, 12%), spirits (1.5oz, 40%), or cocktails (assumes 1.5oz spirits).
Enter hours since first drink — This is when you started, not when you finished. Your body metabolizes alcohol at 0.015% per hour from the moment you begin drinking.
Click Calculate BAC — Review your estimated BAC, impairment level, and time until you're sober or legal to drive.

💡 Pro Tip: For Most Accurate Results

Weigh yourself recently, count drinks carefully (that 16oz craft IPA is 1.3 standard drinks), and be honest about timing. When in doubt, round up on drinks and round down on time—this gives you a more conservative (safer) estimate.

Time to Sober Calculator Tab

Calculate how long until you reach a target BAC level.

Enter your current BAC — Use a result from the BAC calculator, or enter a measurement from a personal breathalyzer.
Select your target — Choose 0.00% for completely sober, 0.08% for the legal limit, or another threshold.
Click Calculate — See how many hours until you reach your target, plus the approximate clock time.

Common mistake: Don't assume you'll be fine to drive just because you're below 0.08%. Even 0.05% BAC significantly impairs driving ability.

BAC Chart Tab

Quick reference showing estimated BAC by weight and number of drinks (for men, after 1 hour).

Find your weight in the left column
Read across to see BAC for 1-6 drinks
Green = safe zone, Yellow = caution, Red = over legal limit
For women: Expect approximately 20-25% higher BAC than shown

Drinks to BAC Calculator Tab

Reverse calculator: how many drinks to reach a specific BAC?

Enter gender, weight, and target BAC — For example, 0.08% is the legal limit.
Enter time period — How long you'd be drinking (e.g., 3 hours at a party).
Review results — See number of standard drinks, plus equivalents in beers, wine glasses, and shots.

⚠️ Important Note

The "Drinks to BAC" calculator shows theoretical maximums. Drinking this amount would put you at the limit—not safely below it. For a margin of safety, plan for fewer drinks than calculated.

Real-World Examples

These examples illustrate how the calculator works in practical situations. All BAC values are calculated using the actual Widmark formula.

Example 1: After-Work Happy Hour

Scenario: Mike, a 180 lb male, has 3 beers over 2 hours at happy hour with coworkers.

Inputs: Male, 180 lbs, 3 drinks (beer), 2 hours

Result: Estimated BAC: 0.046%

What this means: Mike is below the legal limit but not unaffected. At this level, he may feel relaxed with slightly reduced coordination. He could legally drive in most states, but his reaction time is already slower than normal. If he has one more beer, he'll approach the legal limit.

Example 2: Wine with Dinner

Scenario: Sarah, a 140 lb female, has 2 glasses of wine over dinner lasting 1 hour.

Inputs: Female, 140 lbs, 2 drinks (wine), 1 hour

Result: Estimated BAC: 0.065%

What this means: Sarah is in the "caution" zone—legal but impaired. Her judgment and coordination are noticeably affected. She should wait at least 1-2 more hours before driving, or arrange alternative transportation. The same 2 glasses would only put a 180 lb man at about 0.039%.

Example 3: Football Party

Scenario: David, a 200 lb male, has 4 beers over a 3-hour football game.

Inputs: Male, 200 lbs, 4 drinks (beer), 3 hours

Result: Estimated BAC: 0.046%

What this means: Despite drinking more total alcohol than Mike in Example 1, David's higher weight and longer time period result in the same BAC. This shows how weight and time significantly affect BAC. David feels the effects but is below the legal limit.

Example 4: Cocktail Night

Scenario: Jennifer, a 120 lb female, has 3 cocktails over 2 hours at a bar.

Inputs: Female, 120 lbs, 3 drinks (cocktails), 2 hours

Result: Estimated BAC: 0.110%

What this means: Jennifer is well over the legal limit and significantly impaired. At 0.11%, she has slurred speech, poor balance, and severely impaired judgment. She should absolutely not drive and needs to wait approximately 2 hours just to reach the legal limit (and 7+ hours to be completely sober). This example shows how quickly smaller individuals reach dangerous BAC levels.

Example 5: Planning Ahead

Scenario: Tom, a 170 lb male, wants to know how many beers he can have at a 4-hour barbecue while staying under 0.05% BAC.

Using Drinks to BAC tab: Male, 170 lbs, target 0.05%, 4 hours

Result: Approximately 3.4 standard drinks

What this means: Tom can have about 3 beers over 4 hours and stay under 0.05%. This is roughly one beer every 80 minutes. If he drinks faster, his BAC will be higher. This is useful for planning when you want to stay clearly under the legal limit.

Example 6: Morning After

Scenario: Lisa had a night out and estimates her BAC was around 0.12% when she stopped drinking at midnight. She needs to drive at 8am.

Using Time to Sober tab: Current BAC 0.12%, target 0.00%

Result: 8 hours to reach 0.00%

What this means: If Lisa stopped drinking at midnight at 0.12% BAC, she won't be completely sober until 8am. She'd reach the legal limit (0.08%) around 2:40am. This is why "sleeping it off" often isn't enough—alcohol takes longer to metabolize than people expect.

Example 7: Different Drinks, Same Person

Scenario: Compare the same person (160 lb male) drinking different beverages over 1 hour.

Drinks	Alcohol (g)	BAC
2 regular beers (5%)	28g	0.042%
2 glasses wine (12%)	28g	0.042%
2 shots whiskey (40%)	28g	0.042%
2 craft IPAs (7%)	39g	0.064%
2 large glasses wine (8oz)	45g	0.076%

Key insight: Standard drinks of beer, wine, and spirits all contain the same alcohol (14g) and produce the same BAC. But real-world drinks often exceed standard sizes—that's where people get into trouble.

When to Use This Calculator

This BAC calculator is helpful in several situations:

Before You Go Out

Use the "Drinks to BAC" calculator to understand your limits before a social event. Knowing that 3 drinks over 3 hours will put you near the legal limit helps you plan for safe transportation in advance.

During an Event

Check your estimated BAC as you're drinking to stay aware of your impairment level. This isn't about maximizing how much you can drink—it's about understanding when you've crossed from "relaxed" to "impaired."

Before Deciding to Drive

If you're considering driving after drinking, use this calculator to estimate your BAC. However, remember: the safest choice is always not to drive after drinking any amount. Even below the legal limit, alcohol impairs your driving ability.

The Morning After

Estimate whether alcohol from last night is still in your system. Many people are surprised to learn they're still over the legal limit hours after stopping drinking.

Educational Understanding

Learn how factors like weight, gender, and drink type affect BAC. Understanding the science helps you make better decisions about alcohol consumption.

Who Benefits Most

Social drinkers who want to understand their limits
Designated drivers who need to stay under specific thresholds
Health-conscious individuals monitoring their alcohol intake
Students and educators learning about alcohol metabolism
Anyone planning an event where alcohol will be served

Important: This calculator provides estimates only. Never use it to determine if you're safe to drive. Individual factors like food, medications, fatigue, and tolerance mean actual impairment can differ significantly from calculated BAC. When in doubt, don't drive.

Quick Reference Tables

These tables use the actual values from our calculator for quick reference. All data is based on the Widmark formula with standard constants.

Standard Drink Equivalents

One standard drink contains 14 grams of pure alcohol. Here's what that looks like for different beverages:

Beverage	Volume	ABV	Alcohol Content	Standard Drinks
Regular Beer	12 oz (355 ml)	5%	14.0g	1.0
Light Beer	12 oz (355 ml)	4.2%	11.8g	0.8
Craft IPA	12 oz (355 ml)	7%	19.6g	1.4
Strong Ale	12 oz (355 ml)	9%	25.2g	1.8
Table Wine	5 oz (148 ml)	12%	14.0g	1.0
Fortified Wine	5 oz (148 ml)	20%	23.4g	1.7
Spirits (Vodka, Whiskey, etc.)	1.5 oz (44 ml)	40%	13.9g	1.0
Overproof Spirits	1.5 oz (44 ml)	50%	17.4g	1.2
Restaurant Wine Glass	8 oz (237 ml)	12%	22.4g	1.6
Pint of Beer	16 oz (473 ml)	5%	18.7g	1.3

Key insight: Many real-world drinks exceed one standard drink. A restaurant wine pour or a craft beer pint can be 1.3-1.8 standard drinks.

BAC by Weight and Drinks (Men, 1 Hour)

Estimated BAC for men based on body weight and number of standard drinks consumed, after 1 hour of metabolism:

Weight	1 Drink	2 Drinks	3 Drinks	4 Drinks	5 Drinks	6 Drinks
100 lbs	0.03%	0.06%	0.09%	0.12%	0.15%	0.18%
120 lbs	0.02%	0.05%	0.07%	0.10%	0.13%	0.15%
140 lbs	0.02%	0.04%	0.06%	0.09%	0.11%	0.13%
160 lbs	0.01%	0.04%	0.06%	0.07%	0.09%	0.11%
180 lbs	0.01%	0.03%	0.05%	0.06%	0.08%	0.10%
200 lbs	0.01%	0.03%	0.04%	0.06%	0.07%	0.09%
220 lbs	0.01%	0.02%	0.04%	0.05%	0.07%	0.08%
240 lbs	0.01%	0.02%	0.04%	0.05%	0.06%	0.07%

For women: Multiply these values by approximately 1.24 (or add 24%) due to the different Widmark factor (0.55 vs 0.68).

Time to Metabolize Alcohol

Your body eliminates alcohol at a constant rate of 0.015% BAC per hour. Here's how long it takes to metabolize from various starting BACs:

Starting BAC	Status	Time to 0.08%	Time to 0.05%	Time to 0.00%
0.05%	Impaired	Already legal	0 hours	3.3 hours
0.08%	Legal Limit	0 hours	2.0 hours	5.3 hours
0.10%	Intoxicated	1.3 hours	3.3 hours	6.7 hours
0.12%	Intoxicated	2.7 hours	4.7 hours	8.0 hours
0.15%	Very Intoxicated	4.7 hours	6.7 hours	10.0 hours
0.20%	Severely Impaired	8.0 hours	10.0 hours	13.3 hours
0.25%	Severely Impaired	11.3 hours	13.3 hours	16.7 hours
0.30%	Dangerous	14.7 hours	16.7 hours	20.0 hours

💡 Pro Tip: The Morning After

If you were at 0.15% BAC when you stopped drinking at midnight, you won't reach 0.00% until 10:00 AM—and won't be under the legal limit until 4:40 AM. "Sleeping it off" often isn't enough. Calculate before assuming you're safe to drive.

Formula Reference

This calculator uses the Widmark formula, the standard method for BAC estimation used in forensic toxicology, medical settings, and legal proceedings.

The Widmark Formula

BAC = (A / (W × r)) × 100 − (β × t)

Where:

BAC = Blood Alcohol Content (as percentage)
A = Total alcohol consumed (in grams)
W = Body weight (in grams)
r = Widmark factor (gender-based distribution ratio)
β = Metabolism rate (BAC eliminated per hour)
t = Time since drinking began (in hours)

Constants Used in This Calculator

Constant	Value	Explanation
Widmark Factor (Male)	r = 0.68	Men have more body water relative to weight, distributing alcohol more
Widmark Factor (Female)	r = 0.55	Women have less body water, leading to higher BAC for same consumption
Metabolism Rate	β = 0.015%/hour	Average rate at which the body eliminates alcohol (range: 0.010-0.020%)
Alcohol Density	0.789 g/ml	Density of pure ethanol, used to calculate grams from volume
Standard Drink	14 grams	NIAAA definition of alcohol in one standard drink

Calculating Alcohol Content

To determine alcohol in grams from a drink:

Alcohol (g) = Volume (ml) × ABV (decimal) × 0.789

Example: A 12oz (355ml) beer at 5% ABV:

355 × 0.05 × 0.789 = 14.0 grams of alcohol

Complete Calculation Example

Scenario: A 160 lb male drinks 3 beers over 2 hours.

Convert weight to grams: 160 lbs × 453.592 = 72,575 grams
Calculate alcohol consumed: 3 drinks × 14g = 42 grams
Apply Widmark formula: (42 / (72,575 × 0.68)) × 100 = 0.085%
Subtract metabolism: 0.085% − (0.015 × 2) = 0.085% − 0.030% = 0.055% BAC

Understanding Your Results

This calculator categorizes BAC levels based on typical effects. Individual responses vary significantly based on tolerance, medications, fatigue, and other factors.

BAC Levels and Effects

BAC Range	Status	Typical Effects	Driving Risk
0.00% - 0.02%	Minimal	No significant effects; you may feel slightly relaxed	Minimal impairment
0.02% - 0.05%	Relaxed	Mild relaxation, slight euphoria, minor impairment of judgment	Some impairment begins
0.05% - 0.08%	Impaired	Reduced coordination, judgment noticeably affected, lowered inhibitions	Significantly impaired
0.08% - 0.15%	Intoxicated	Significant impairment, slurred speech, poor balance, impaired vision	Illegal to drive; high crash risk
0.15% - 0.30%	Severely Impaired	Major loss of coordination, vomiting possible, blackouts may occur	Extremely dangerous
0.30%+	Dangerous	Risk of unconsciousness, alcohol poisoning, medical emergency	Life-threatening

Color Coding

Throughout this calculator and website, we use consistent color coding:

■ Green (Safe) — BAC below 0.05%. Legal to drive but some impairment may be present.
■ Yellow (Caution) — BAC 0.05% to 0.08%. Noticeably impaired. Legal in most states but driving not recommended.
■ Red (Danger) — BAC 0.08% and above. Over the legal limit. Do not drive.

Important Limitations

These results are estimates only. Actual BAC can differ due to:

Food in stomach — Eating slows absorption; drinking on an empty stomach raises BAC faster
Drinking speed — Rapid consumption causes higher peak BAC than the same drinks spread over time
Individual metabolism — Some people metabolize faster (0.020%) or slower (0.010%) than average
Body composition — More muscle mass = more body water = lower BAC for same consumption
Medications — Many drugs interact with alcohol and affect both BAC and impairment
Health conditions — Liver disease, diabetes, and other conditions affect alcohol processing

Comparison: How Different Factors Affect BAC

These side-by-side comparisons show how weight, gender, and time dramatically affect BAC for the same number of drinks.

Same Drinks, Different Weights (Men)

Scenario: 3 beers consumed over 1 hour

Weight	Gross BAC	After 1hr Metabolism	Status	Time to Legal (0.08%)
140 lbs	0.092%	0.077%	Just under limit	Already legal
160 lbs	0.080%	0.065%	Impaired	Already legal
180 lbs	0.071%	0.056%	Impaired	Already legal
200 lbs	0.064%	0.049%	Relaxed	Already legal
220 lbs	0.058%	0.043%	Relaxed	Already legal

Key insight: A 140 lb person reaches nearly twice the BAC of a 220 lb person drinking the same amount.

Same Weight, Different Genders

Scenario: 150 lbs, 2 glasses of wine, 1 hour

Gender	Widmark Factor	BAC (Gross)	BAC (After 1hr)	Difference
Male	r = 0.68	0.060%	0.045%	Baseline
Female	r = 0.55	0.075%	0.060%	+33% higher

Key insight: Women reach approximately 24-33% higher BAC than men of the same weight drinking the same amount.

Same Drinks, Different Time Periods

Scenario: 160 lb male, 4 beers

Time Period	Gross BAC	Metabolized	Final BAC	Status
1 hour	0.107%	0.015%	0.092%	Over legal limit
2 hours	0.107%	0.030%	0.077%	Just under limit
3 hours	0.107%	0.045%	0.062%	Impaired
4 hours	0.107%	0.060%	0.047%	Relaxed
5 hours	0.107%	0.075%	0.032%	Minimal effects

Key insight: Spacing drinks over time dramatically reduces BAC. The same 4 drinks are over the limit in 1 hour but well under by 4 hours.

Legal Limits by Category (United States)

Driver Category	BAC Limit	Notes
Standard (21+)	0.08%	All 50 states (Utah: 0.05%)
Commercial (CDL)	0.04%	Applies when operating commercial vehicle
Under 21	0.00% - 0.02%	Zero tolerance; varies by state
Ride-share Drivers	0.00%	Company policies typically require zero BAC

Remember: Impairment begins well before the legal limit. Even at 0.05% BAC, your driving ability is significantly reduced.

Key Alcohol Facts at a Glance

Understanding these fundamental numbers is essential for making informed decisions about alcohol consumption.

14g

Standard Drink

Pure alcohol in one standard drink

0.015%

Per Hour

BAC your body eliminates hourly

0.08%

Legal Limit

Driving limit in 49 US states

0.00%

Only Safe BAC

The only truly safe level to drive

24%

Higher BAC

Women vs men of equal weight

6-8 hrs

Sleep It Off?

May still be impaired after night out

0.02%

Impairment Starts

Crash risk increases at this level

38%

Traffic Deaths

US fatalities involving alcohol

Crash Risk by BAC Level

Research from the National Highway Traffic Safety Administration shows crash risk increases exponentially with BAC. Even small amounts of alcohol dramatically raise your chances of being in a crash.

0.00% BAC

0.02% BAC

1.4x

0.05% BAC

0.08% BAC

0.10% BAC

0.12% BAC

12x

0.15% BAC

25x higher risk

25x

Key takeaway: At the legal limit (0.08%), you're already 4 times more likely to crash. At 0.15%, you're 25 times more likely. There is no "safe" level of impaired driving.

How Alcohol Travels Through Your Body

Understanding the journey alcohol takes through your body explains why BAC rises and falls the way it does.

Mouth & Esophagus

A small amount of alcohol is absorbed immediately through the lining of your mouth. Most passes quickly to your stomach.

Seconds after drinking

Stomach

About 20% of alcohol is absorbed through the stomach lining. Food in the stomach slows this process significantly—eating before drinking can reduce peak BAC by up to 50%.

5-10 minutes

Small Intestine

The remaining 80% of alcohol is absorbed through the small intestine, which has a much larger surface area. This is where most absorption occurs.

15-30 minutes

Bloodstream & Peak BAC

Alcohol enters the blood and distributes throughout your body. BAC peaks 30-90 minutes after your last drink, depending on food, drink type, and drinking speed.

30-90 minutes to peak BAC

Brain

Alcohol crosses the blood-brain barrier and affects neurotransmitters—particularly GABA (inhibitory) and glutamate (excitatory). This causes relaxation, impaired judgment, and slowed reaction times.

Minutes after entering blood

Liver (Metabolism)

Your liver metabolizes 90-95% of alcohol using the enzyme alcohol dehydrogenase (ADH). This happens at a constant rate of about 0.015% BAC per hour. Nothing can speed this up.

0.015% per hour, continuously

Elimination

The remaining 5-10% is eliminated unchanged through breath (what breathalyzers measure), urine, and sweat. Complete elimination depends on how much you drank.

Until BAC reaches 0.00%

What Does One Standard Drink Look Like?

All of these contain approximately 14 grams of pure alcohol and count as one standard drink. Many real-world servings exceed these amounts.

🍺

Regular Beer

12 oz (355 ml)
5% ABV

14g alcohol

🍷

Wine

5 oz (148 ml)
12% ABV

14g alcohol

🥃

Spirits

1.5 oz (44 ml)
40% ABV

14g alcohol

🍸

Fortified Wine

3.5 oz (103 ml)
17% ABV

14g alcohol

🧉

Malt Liquor

8 oz (237 ml)
7% ABV

14g alcohol

Common Drinks That Exceed One Standard Drink

Many popular drinks contain more alcohol than you think:

Standard beer

1.0 drinks

1.0x

Pint of beer

1.3 drinks

1.3x

Craft IPA (7%)

1.4 drinks

1.4x

Restaurant wine

1.6 drinks

1.6x

Strong ale (9%)

1.8 drinks

1.8x

Margarita

2-3 drinks

2-3x

Long Island

3-4 drinks

3-4x

Watch out: A single Long Island Iced Tea can contain 3-4 standard drinks. Two of these over an hour could put a 160 lb male well over the legal limit at approximately 0.14% BAC.

BAC Impairment Scale: Effects at Every Level

This visual scale shows the progressive effects of alcohol on your body and mind. Each level builds on the previous one.

0.01-0.03%

Subtle Effects

Slight mood elevation, mild relaxation. Most people feel normal. Average person: 1 drink in the first hour.

0.03-0.05%

Mild Impairment

Lowered inhibitions, slightly impaired judgment, feeling of warmth. Concentration begins to decline. Reaction time slightly slower.

0.05-0.08%

Clearly Impaired

Reduced coordination and balance, impaired reasoning, exaggerated emotions. Depth perception and peripheral vision affected. Driving ability significantly reduced.

0.08-0.12%

Legally Intoxicated

Slurred speech, poor muscle coordination, impaired self-control, impaired perception and judgment. Reaction time significantly delayed. Driving is illegal.

0.12-0.20%

Severe Impairment

Vomiting likely, significant loss of motor control, blurred vision, major loss of balance. Blackouts may begin. Judgment is severely compromised.

0.20-0.30%

Confusion & Stupor

Disorientation, need help to stand or walk, may lose consciousness. Risk of choking on vomit, severe injury from falls.

0.30%+

Life-Threatening

Loss of consciousness, dangerously slow breathing, low body temperature, potential cardiac arrest. Alcohol poisoning. Call 911 immediately.

BAC Over Time: How Your Level Rises and Falls

This chart shows estimated BAC for a 160 lb male who has 4 beers, one every 30 minutes from 8:00-9:30 PM. BAC peaks after the last drink is absorbed and then declines at 0.015% per hour.

0.08% Legal Limit

8 PM