BAC After One Beer
The BAC after one beer is about 0.028% in a 160 lb (73 kg) man and 0.040% in a 140 lb (64 kg) woman once it is absorbed. That assumes a 12 oz beer at 5%, which holds 14 grams of alcohol. The number then falls by about 0.015% per hour.
A 12 oz beer at each body weight
Lightest to heaviest, the same can runs from 0.056% for a 100 lb woman down to 0.019% for a 240 lb man, roughly a threefold spread. In the US, what counts as one standard drink is 14 g; some countries use less.
Each row is one 12 oz beer at 5% run through the Widmark formula (r 0.68 or 0.55, minus 0.015% per hour). "All absorbed" is the top figure with no time passed, and "1 hour" counts from the first sip.
| Body weight | Men, all absorbed | Women, all absorbed | Men, 1 hour | Women, 1 hour |
|---|---|---|---|---|
| At 100 lb (45 kg) | 0.045% | 0.056% | 0.030% | 0.041% |
| At 120 lb (54 kg) | 0.038% | 0.047% | 0.023% | 0.032% |
| At 140 lb (64 kg) | 0.032% | 0.040% | 0.017% | 0.025% |
| At 160 lb (73 kg) | 0.028% | 0.035% | 0.013% | 0.020% |
| At 180 lb (82 kg) | 0.025% | 0.031% | 0.010% | 0.016% |
| At 200 lb (91 kg) | 0.023% | 0.028% | 0.008% | 0.013% |
| At 220 lb (100 kg) | 0.021% | 0.026% | 0.006% | 0.011% |
| At 240 lb (109 kg) | 0.019% | 0.023% | 0.004% | 0.008% |
These figures are estimates for an average body, and pour size, pace and food shift a reading up or down. Your own weight, drinks and hours go into the BAC calculator, which runs the same math.
BAC after one beer poured as a pint
A 16 oz pint at 5% holds 18.7 g, or 1.33 standard drinks. On a 130 lb (59 kg) woman, that single pint reads 0.058% all absorbed and 0.043% an hour after her first sip.
BAC after 2 drinks, then 3 and 4
Each extra standard drink adds roughly the one-drink figure again. For a 160 lb man that step is about 0.028%, so his BAC after 2 drinks is 0.042% at 1 hour and after 4 drinks 0.098%. A 160 lb woman's step is about 0.035%, and how many drinks reach 0.08% turns that step into drink counts.
All drinks are finished within the first hour and read at 1 hour. A 1 hour reading may still be climbing, since BAC rises for a while after the last sip, as when BAC peaks and what each level means sets out.
| Drinker | One drink | Two drinks | Three drinks | Four drinks |
|---|---|---|---|---|
| Woman, 140 lb (64 kg) | 0.025% | 0.065% | 0.105% | 0.145% |
| Man, 140 lb (64 kg) | 0.017% | 0.050% | 0.082% | 0.115% |
| Woman, 160 lb (73 kg) | 0.020% | 0.055% | 0.090% | 0.125% |
| Man, 160 lb (73 kg) | 0.013% | 0.042% | 0.070% | 0.098% |
| Woman, 200 lb (91 kg) | 0.013% | 0.041% | 0.069% | 0.097% |
| Man, 200 lb (91 kg) | 0.008% | 0.030% | 0.053% | 0.076% |
Past four drinks and outside these three weights, the BAC chart by weight runs the same math up to 8 drinks and 260 lb. The US adult limit is 0.08%, lower in Utah and for drivers under 21 or commercial drivers, as listed in BAC limits by state. The Centers for Disease Control and Prevention (CDC) warns that driving is affected at BAC levels lower than 0.08%.
Beer vs wine vs shots in BAC numbers
By grams, a regular can of beer, a standard glass of wine and a single shot of spirits come out level at about 14 g each. The formula therefore gives the same BAC after one drink for each. Once absorbed, each one lifts the 160 lb man in the table to 0.028% and the 140 lb woman to 0.040%. How fast each type hits is a separate question, answered under whether shots get you drunk faster.
What would your BAC be after 2 shots
Two 1.5 oz shots at 40% hold 28.0 g, exactly 2 standard drinks, so they match the 2-drink row above. A man of 175 lb (79 kg) lands at 0.052% all absorbed, or 0.037% an hour after the first shot.
BAC per beer for pints, IPAs and craft beer
The beer in your hand is often more than one drink. The National Institute on Alcohol Abuse and Alcoholism (NIAAA) rates a strong 10% craft beer as two drinks. The BAC per beer columns below assume no time has passed.
| Pour | Alcohol | Standard drinks | 160 lb (73 kg) man | 140 lb (64 kg) woman |
|---|---|---|---|---|
| 12 oz light beer, 4.2% | 11.8 g | 0.84 drinks | 0.024% | 0.034% |
| 12 oz regular beer, 5% | 14.0 g | 1.00 drink | 0.028% | 0.040% |
| 16 oz pint, 5% | 18.7 g | 1.33 drinks | 0.038% | 0.053% |
| 16 oz IPA labeled 7% | 26.1 g | 1.87 drinks | 0.053% | 0.075% |
| 24 oz can, 5% | 28.0 g | 2.00 drinks | 0.057% | 0.080% |
| 12 oz craft beer, 10% | 28.0 g | 2.00 drinks | 0.057% | 0.080% |
| 5 oz wine, 12% | 14.0 g | 1.00 drink | 0.028% | 0.040% |
| 1.5 oz shot, 40% | 14.0 g | 1.00 drink | 0.028% | 0.040% |
| 750 mL bottle of wine, 12% | 71.0 g | 5.07 drinks | 0.144% | 0.203% |
The last row reaches 0.144% for him and 0.203% for her, levels where the warning signs under alcohol poisoning BAC levels matter. Two 16 oz pints at 5% hold 37.3 g, or 2.67 drinks. All absorbed, that is about 0.076% for the 160 lb man and 0.107% for the 140 lb woman.
What a US beer label tells you
Federal rules let most US beers leave ABV off the label. ABV "may be stated" unless state law prohibits it, and it is required when alcohol comes from added flavors. A printed ABV may be off by up to 0.3 percentage points either way, so a can labeled 5.0% can hold 4.7% to 5.3%.
Two drinks in 30 minutes vs 3 hours
The same 2 drinks give a higher figure when finished fast: 0.049% for a 160 lb man at 30 minutes against 0.012% over 3 hours.
Each figure is read when the second drink is finished, timed from the first sip.
| Time to finish 2 drinks | 160 lb (73 kg) man | 140 lb (64 kg) woman |
|---|---|---|
| 30 minutes | 0.049% | 0.073% |
| 1 hour | 0.042% | 0.065% |
| 2 hours | 0.027% | 0.050% |
| 3 hours | 0.012% | 0.035% |
A small brewer-run pilot in 18 fasting Japanese adults also found a lower reading at 75 minutes when one 480 mL beer was sipped over 2 hours. By 75 minutes, that slow group had drunk only about 280 mL.
FAQ
How much does your BAC go up per drink?
One US standard drink adds about 0.019% to 0.056% once absorbed for adults from 100 to 240 lb, women at the higher end. Australia's SA Health quotes 0.01% to 0.03% per drink within an hour, partly because its standard drink is smaller than 14 g.
Do vodka, tequila and whiskey raise BAC differently?
Not by grams. A 1.5 oz shot of any of them at 40% ABV holds about 14 g, so the formula treats them alike. Pour size, label strength, drinking speed and the mixer change the result.
What BAC do 4 drinks give a short woman?
The formula uses weight, not height, so a 5 ft 3 woman starts from her weight. At 140 lb (64 kg), 4 drinks finished within an hour come to about 0.145% one hour after the first sip.
How much of one beer remains after an hour?
An hour after the first sip, the BAC after one beer of 12 oz still sits near 0.013% for a 160 lb man and 0.025% for a 140 lb woman. The rest leaves at about 0.015% an hour, and the hours from any BAC back to 0.00 come with the range of real clearance speeds.
Why is my BAC high after just one drink?
Usually the drink held more than 14 g: a pint, an IPA, a strong craft beer or an inexact label. A smaller body raises the figure, and an empty stomach speeds absorption.
Conclusion
A beer equals one drink only at 12 oz and about 5%, so the pour and the label decide which line of the tables is yours. A 16 oz pint already holds 1.33 drinks, and a 24 oz can holds 2. Only hours bring the number down, which is why coffee or a cold shower will not sober you up.
