BAC Chart: Blood Alcohol Content by Weight and Drinks

Section 1

How to Read This BAC Chart

Find your body weight in the left column and the number of drinks you plan to have, or have had, across the top row. The cell where they intersect shows your estimated BAC. The colour tells you the broad risk level at a glance: green means minimal effect, yellow means you may be over the limit in some countries, and orange or red means you are over the legal driving limit almost everywhere.

This chart uses the US standard drink definition: one drink equals 14 grams of pure alcohol. That is approximately one 12 oz regular beer at 5%, one 5 oz glass of wine at 12%, or one 1.5 oz shot of spirits at 40%. If your actual drinks are larger, stronger, or both, your real BAC will be higher than the chart shows. A pint of 6% IPA counts as roughly 1.6 standard drinks. For more conversions, see the standard drink sizes guide.

BAC charts are planning tools, not precision instruments. They use average Widmark constants and do not account for food intake, drinking speed, individual enzyme activity, medications, or liver health. Two people with identical weight, sex, and drink count can have meaningfully different actual BAC levels. Use the full BAC calculator for a more personalised estimate that accounts for drinking time and session length.

Section 2

What Each BAC Level Feels Like

The numbers in the chart correspond to measurable changes in coordination, judgment, and reaction time. The table below maps BAC ranges to their typical effects - the same data that powers the effect descriptions in the chart's detail panel.

To compare chart estimates with detection windows after drinking, read how long does alcohol stay in your system.

Section 3

Legal BAC Limits Around the World

The legal driving limit varies significantly by country, and within some countries by driver category. The chart above defaults to the US limit of 0.08%, but selecting your country updates the limit marker in real time. The tables below show limits for major countries and driver categories.

Zero or near-zero tolerance (0.00-0.02%)

Standard limit (0.05%)

Higher limit (0.08%)

For the complete 78-country reference, see the Alcohol Laws by Country guide. Limits shown are for standard adult drivers. Professional drivers, learner drivers, and under-age drivers often face stricter limits, so check your local regulations.

Section 4

Why Men and Women Have Different BAC Charts

The BAC chart shows different values for men and women at the same weight and drink count because of two biological differences. First, women have a lower average percentage of body water than men of the same weight - roughly 52% vs 61%. Because alcohol distributes through body water, a smaller water volume means higher alcohol concentration from the same dose.

Second, women have lower activity of alcohol dehydrogenase in the stomach lining, which means less alcohol is broken down before it enters the bloodstream - a process called first-pass metabolism. The result is that more of each drink reaches the blood as active alcohol. This difference is captured in the Widmark distribution constant: approximately 0.73 for men and 0.66 for women in this chart formula.

In practical terms, a 140 lb woman and a 140 lb man drinking the same four drinks will have meaningfully different BAC levels. This is not a tolerance difference; it is a pharmacokinetic difference that exists regardless of drinking experience or habit. The toggle at the top of the chart switches between the two Widmark constants so the numbers reflect this difference.

Section 5

The Formula Behind the Chart

Every cell in the chart is calculated using a Widmark-style formula, the same broad approach used for BAC estimation in law enforcement, courts, and medical contexts. For the deeper model and its limits, read how BAC works.

BAC = (A x 5.14) / (W x r) - (0.015 x H)

The chart assumes all drinks are consumed within one hour and uses standard US drink sizes, with 0.6 fl oz of pure alcohol per drink. This produces a peak BAC estimate shortly after drinking ends. For sessions spread over several hours, the full BAC calculator accounts for ongoing elimination during drinking and will usually produce a lower final BAC than the chart suggests.

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FAQ

BAC Chart FAQ

Common questions about reading BAC tables, legal thresholds, and why chart estimates differ by body and sex.