When Can I Drive After 4 Beers?
Four beers is a significant amount of alcohol for almost anyone. Whether you are at a sports bar, a party, or a casual gathering, four standard drinks consumed over an evening will put the vast majority of adults over the legal driving limit. Here is what the numbers actually say, broken down by weight and sex.
Use our free BAC calculator to get a personalised estimate based on your weight, sex, and drinks.
Calculate Your BAC Now →The Math: How BAC Is Calculated
BAC is calculated using the Widmark formula: BAC = (ethanol grams × 100) / (weight_kg × r × 1000), where r = 0.68 for males and r = 0.55 for females, and weight_kg = lb / 2.205.
Four standard US beers (355 ml each at 5% ABV) contain approximately 56 grams of ethanol — equivalent to 4 standard drinks. Alcohol is then eliminated at approximately 0.015% BAC per hour. The table below shows peak BAC (no metabolism during drinking) and the hours needed to reach key thresholds.
BAC Chart for 4 Standard Beers by Weight and Sex
Peak BAC immediately after consuming 4 standard beers, before any metabolism is applied. Hours to 0.08% and 0.00% are calculated from this peak at 0.015%/hr.
| Weight | Male BAC | Female BAC | Male → 0.08% | Female → 0.08% | Male → 0.00% | Female → 0.00% |
|---|---|---|---|---|---|---|
| 120 lb | 0.151% | 0.187% | 4.7 hrs | 7.1 hrs | 10.1 hrs | 12.5 hrs |
| 140 lb | 0.130% | 0.160% | 3.3 hrs | 5.3 hrs | 8.7 hrs | 10.7 hrs |
| 160 lb | 0.113% | 0.140% | 2.2 hrs | 4.0 hrs | 7.5 hrs | 9.3 hrs |
| 180 lb | 0.101% | 0.125% | 1.4 hrs | 3.0 hrs | 6.7 hrs | 8.3 hrs |
| 200 lb | 0.091% | 0.112% | 0.7 hrs | 2.1 hrs | 6.1 hrs | 7.5 hrs |
| 220 lb | 0.083% | 0.102% | 0.2 hrs | 1.5 hrs | 5.5 hrs | 6.8 hrs |
Use our free BAC calculator to get a personalised estimate based on your weight, sex, and drinks.
Calculate Your BAC Now →What If You Drank Over More Than 1 Hour?
If you spread 4 beers over a 4-hour period (a common pace at a long dinner or evening out), your body eliminates 4 × 0.015% = 0.060% during that time. For a 180 lb male with a peak BAC of 0.086%, the effective BAC at the end of 4 hours would be approximately 0.026% — under the limit. However, spreading drinks over time rarely happens precisely, and you should calculate with your actual drinking pattern.
What Factors Make Your BAC Higher or Lower?
- Body composition: Higher body fat percentage (less body water) means higher BAC per drink. Muscular individuals may have lower BAC than the table suggests.
- Food: Eating before or during drinking slows alcohol absorption and reduces peak BAC by up to 50%. The table assumes drinking without food.
- Drinking speed: Spreading drinks over more time allows metabolism to offset absorption, reducing peak BAC. The table shows worst-case (all drinks at once).
- Tolerance: Tolerance affects how drunk you feel, not your actual BAC. A high-tolerance drinker feels less impaired at 0.10% but is equally impaired on measurable tests.
- Medications: Many medications interact with alcohol and can raise effective BAC or increase impairment.
The Bottom Line: When Is It Safe to Drive?
Four beers means you should plan not to drive for at least 4–7 hours after your last drink, depending on your weight and sex. Lighter individuals and women may need to wait 8–12 hours. If you had 4 IPAs or craft beers at higher ABV, add significant time on top of these figures. The morning-after check is particularly important with 4+ drinks consumed.
The legal limit in most US states is 0.08%. Utah's limit is 0.05%. Commercial drivers face a 0.04% limit. International limits are often lower (0.05% in most of Europe, 0.02% in Sweden and Poland). If you are driving internationally or professionally, use the appropriate threshold.
When in doubt, do not drive. A ride-share, taxi, or designated driver is always the right call.
Use our free BAC calculator to get a personalised estimate based on your weight, sex, and drinks.
Calculate Your BAC Now →Frequently Asked Questions
How long after 4 beers can I drive?
For a 180 lb male, 4 beers produces approximately 0.086% BAC. Hours to 0.08%: about 0.4 hours. Hours to 0.00%: about 5.7 hours. For a 130 lb female, peak BAC is about 0.179%, requiring nearly 12 hours to clear. Use the table above for your specific weight.
Is 4 beers a lot?
Four standard drinks is above the 'low-risk drinking' threshold (1 drink/day for women, 2 for men) defined by health guidelines. Consumed within an hour, 4 beers will put virtually everyone over the legal driving limit.
Can I drive the morning after 4 beers?
If you had 4 beers before midnight and wake up at 7 a.m. (7 hours later), a 160 lb male would have cleared: 7 × 0.015% = 0.105% from his peak BAC of 0.114%, landing at about 0.009% — just above zero. A 130 lb female would have a peak of about 0.141%, still at 0.036% at 7 a.m. It depends on your numbers.
Disclaimer: This article is for educational purposes only and does not constitute legal or medical advice. BAC estimates are approximations. Individual results vary based on body composition, food intake, health status, and other factors. Never drive if you feel impaired. When in doubt, don't drive.