Blood Alcohol Calculator

Blood Alcohol Calculator

Fluid ounces consumed:
Alcohol content of drink (%):
Hours spent drinking:
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Blood Alcohol Formula:

Blood Alcohol Content (Male) = (Fluid Ounces Consumed x 5.14/Weight x .73) - .015 x Hours Spent Drinking

Blood Alcohol Content (Female) = (Fluid Ounces Consumbed x 5.14/Weight x .66) - .015 x Hours Spent Drinking

Blood Alcohol Definition

This FREE online Blood Alcohol Calculator gives you a rough estimate of how much alcohol is in your blood. Before you face a breathalyzer or a blood test from the police, or worse, become the drunk driver in an alcohol related crash, use this calculator to help determine whether you are within the legal limit. Try this FREE calculator today!

In most U.S. states, the legal limit for drivers is 0.08% and may be even less for drivers under 21. If the blood alcohol calculator shows a percentage anywhere near or above that, it is best to hold off on driving. This health calculator will make sure you are within the limits!

How much alcohol is in your blood depends on several factors. This Blood Alcohol Calculator takes all of the following into account:

1. Fluid Ounces Consumed

Though this is usually a rough estimate, there are some general guidelines. A serving of beer is usually between 12 and 16 ounces. A typical glass of wine is around 5 ounces, with a standard 750 mL bottle containing five 5 ounce servings. Mixed drinks often have around 1.5% ounces of the alcoholic spirit per serving; however, this amount varies quite a bit.

2. Alcohol Content (%) of the Drink(s)

Typically, this can be found on the bottle, often in fine print. Most beers are between 4.5% and 6% alcohol by volume; wine usually ranges from 10% to 15%; and spirits can be anywhere from 15% to 100% alcohol by volume. If you are drinking in a bar or restaurant and do not have the bottle, it is worth your while to ask your server about the alcohol content of your drink.

3. Hours Spent Drinking

If this includes an amount less than an hour, enter that amount as a decimal: 0.5 for half an hour, 1.25 for an hour and fifteen minutes, etc.

4. Gender

Men and women metabolize alcohol at different rates, so this is relevant. Even if a man and a woman are the same height and weight and drink the same amount of alcohol in the same amount of time, the woman is likely to become intoxicated faster and stay intoxicated longer.

Differences in body fat percentage, water concentration in the body, amount of the enzymes the liver depends on to metabolize alcohol, and hormones all serve to account for this. The same woman may take more or less time to metabolize alcohol depending on where she is in her menstrual cycle. Women on hormonal contraceptives take longer than women who are not.

5. Weight

Heavier people can usually tolerate more alcohol than lighter people before they become intoxicated, simply because of how much body they have for the alcohol to circulate through. Many traditional charts used to estimate blood alcohol percentage use weight as the main relevant factor.

This Blood Alcohol Calculator can only provide a rough estimate of your blood alcohol percentage. Though it covers the main relevant factors, there are many more factors in determining how intoxicated you are that it does not take into account. Individuals vary greatly in how fast they metabolize alcohol and how strongly they are affected by it, even among people of the same size and gender. How recently you have eaten is also a contributing factor: if you drink on an empty stomach, it will affect you more strongly than if you drink during or after a meal. Finally, the calculator does not account for women’s cycle related differences or the effects of health conditions or medications on alcohol metabolism.

Try this online calculator today!

How to Calculate Blood Alcohol

Let's be honest - sometimes the best blood alcohol calculator is the one that is easy to use and doesn't require us to even know what the blood alcohol formula is in the first place! But if you want to know the exact formula for calculating blood alcohol then please check out the "Formula" box above.

Add a Free Blood Alcohol Calculator Widget to Your Site!

You can get a free online blood alcohol calculator for your website and you don't even have to download the blood alcohol calculator - you can just copy and paste! The blood alcohol calculator exactly as you see it above is 100% free for you to use. If you want to customize the colors, size, and more to better fit your site, then pricing starts at just $29.99 for a one time purchase. Click the "Customize" button above to learn more!