Blood Alcohol Concentration (BAC) Calculator 🇮🇪

Calculate your estimated Blood Alcohol Concentration (BAC) instantly. Track standard drinks, view sobriety charts, and check your status against the 50mg (0.05%) Irish legal limit.

Do you fancy AI? Try our AI-powered BAC calculator.

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CONTEXT

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ABOUT YOU

Sex

👨 Male 👩 Female

Weight

Start time of drinking (optional)

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🍺 🍷 🥃 🍺 🍹 🥂

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The results will show up here...

Current BAC

Measured for Now

Legal limit

Based on Irish law

Elimination rate

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Assumed average

Standard Drinks

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Approx. consumed

Pure Alcohol

Pure alcohol consumed

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	🟢 Status indicators
🔴	Above the legal limit – do not drive.
🟡	Close to the legal limit – driving not recommended.
🟢	Safe to drive, but stay cautious.

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📉 Sobriety Over Time

👮 Health impact and legal consequences

Legal limit reached in: {{ legalLimitTimeLabel }} Sober in: {{ sobrietyTime }} Peak BAC: {{ peakBAC }}

💡 Tips: drink water, eat, and avoid driving until below the legal limit and ideally sober.

About results ▼

📊 Current BAC

Your Current BAC shows your estimated blood alcohol concentration right now as a percentage. This number reflects how much alcohol is in your bloodstream.

🚔 Legal limit

In Ireland, the standard legal driving limit is 0.05% BAC (50mg per 100ml of blood). For learners and professional drivers, the limit is 0.02% BAC. Exceeding this results in mandatory disqualification.

🧪 Elimination rate

This shows the assumed average rate your body metabolizes alcohol — typically ~0.015 % BAC per hour.

🍺 Standard Drinks

The number of Standard Drinks represents the approximate number of typical servings you’ve consumed. In Ireland, a standard drink contains 10 grams of alcohol.

🧴 Pure Alcohol

Total alcohol absorbed so far.

⏱ Time vs. Sobriety Table

The table lists how your BAC is expected to change with each hour passed. Icons or status indicators show whether the level is safe for driving.

📈 Sobriety Over Time Graph

A visual line chart plotting your estimated BAC decline over hours. It helps you see when your BAC drops below the Irish drink drive limit.

Data used for calculations

In order to accurately calculate the effects of alcohol on the body, the following important data are required:

Weight (kg):: Body mass has a direct impact on the absorption of alcohol.
Gender: The bodies of women and men process alcohol differently.
Amount of alcohol consumed (ml): It is necessary to indicate the exact volume.
Alcoholic strength (%): This indicator shows the concentration of ethanol.
The time of the first drink (optional): Allows you to see your estimated sobriety for the current clock time.

Drink Driving in Ireland

Alcohol driving limits in Ireland:

For experienced drivers: 50mg of alcohol per 100ml of blood (0.05% BAC).

For learner and professional drivers:

A limit of 20mg of alcohol per 100ml of blood (0.02% BAC) applies.

Road Traffic Act:

Strict penalties apply for exceeding these limits in Ireland.

Penalties for Drink Driving in Ireland

Fines and Disqualification
- Exceeding the limit results in an automatic disqualification from driving for at least 3 months and a fine of up to €200.
Serious Offenses
- Higher BAC levels can lead to fines of up to €5,000 and/or imprisonment for up to 6 months.
Licence Suspension
- Mandatory disqualification periods apply to all drink-driving convictions.

Tips for Responsible Drinking

Limit your alcohol consumption – follow the “one drink per hour” rule.
Consume alcohol with meals to slow down its absorption.
Drink a glass of water after each alcoholic drink.
Plan ahead: use public transport, a taxi, or a designated driver.

Source: Road Safety Authority (RSA) Ireland.