How Many Units Can You Have While Drinking? Understanding Your Limits

November 22, 2025 •

2 min read

Fact: The UK Chief Medical Officers advise that both men and women should not regularly drink more than 14 units a week to keep health risks low. This guideline helps clarify how many units can you have while drinking, emphasizing the importance of responsible consumption.

Quick Summary

This guide explains how to calculate alcohol units based on strength and volume, detailing official national guidelines. It covers influential factors like weight and metabolism, and outlines the short-term and long-term health risks associated with excessive consumption.

Key Points

Weekly Limit: Both men and women are advised not to regularly exceed 14 units of alcohol per week to keep health risks low.
Unit Definition: One UK alcohol unit is 10ml of pure alcohol, while one US standard drink is about 14 grams of pure alcohol.
Calculating Units: You can calculate units by multiplying the drink's volume (ml) by its ABV% and dividing by 1,000.
Spread Consumption: The weekly unit limit should be spread over at least three days, with several alcohol-free days included.
Influencing Factors: Personal factors like weight, gender, and food intake significantly affect how your body processes alcohol.
Binge Drinking Dangers: Consuming the weekly unit limit in one session, or binge drinking, is much more harmful than spreading it out.

Demystifying the Alcohol Unit

An alcohol unit is a standardized measure of pure alcohol in a drink, helping people monitor consumption. In the UK, one unit is 10ml (or 8g) of pure ethanol. The US uses a 'Standard Drink' with about 14 grams of pure alcohol. Knowing how to calculate units is key to responsible drinking.

Calculate units with this formula: (Volume in ml x ABV%) / 1,000 = Units. For example, a 175ml glass of 12% ABV wine is 2.1 units. A pint (568ml) of 4% ABV beer is about 2.3 units, and a 25ml shot of 40% ABV spirit is 1 unit.

National Drinking Guidelines Explained

Countries have varying guidelines for low-risk drinking to minimize health risks. The {Link: Drinkaware website https://www.drinkaware.co.uk/facts/information-about-alcohol/alcohol-and-the-facts/low-risk-drinking-guidelines} provides details on UK guidelines. The {Link: NIAAA website https://www.niaaa.nih.gov/alcohols-effects-health/what-standard-drink} offers information on US standard drinks and consumption limits.

Comparison of Alcohol Units and Standard Drinks

This table compares UK units and US standard drinks for common beverages at typical ABV levels. Note that ABV can vary.


Beverage (Example)	Volume	Typical ABV	UK Units	US Standard Drinks
Pint of Beer	568ml (UK pint)	4%	~2.3	~1.6
Bottle of Beer	330ml	5%	~1.7	~1.2
Medium Glass Wine	175ml	12%	~2.1	~1.5
Large Glass Wine	250ml	12%	~3.0	~2.1
Single Shot Spirits	25ml (UK measure)	40%	~1.0	~0.7
Double Shot Spirits	50ml	40%	~2.0	~1.4

Factors that Influence Alcohol Tolerance

Personal factors affect how alcohol impacts you. Key factors include weight, gender, metabolism, food intake, medication, and frequency of drinking.

Short-Term and Long-Term Health Risks

Exceeding unit limits has immediate and delayed health consequences. Short-term risks include accidents, poor judgment, anxiety, slurred speech, impaired coordination, and alcohol poisoning. Long-term risks involve organ damage (liver, brain, heart), increased cancer risk, cardiovascular issues, mental health problems, and dependency.

Conclusion: Finding a Healthy Balance

Understanding how many units can you have while drinking, along with national guidelines and personal factors, is crucial for minimizing health risks. Tracking intake and taking alcohol-free days are key to a healthier approach. If concerned about drinking habits, seek professional help. More information can be found on the {Link: NHS website https://www.nhs.uk/live-well/alcohol-advice/}.

Frequently Asked Questions

An alcohol unit is a UK-based measure of 10ml of pure alcohol, while a US standard drink contains about 14 grams of pure alcohol. Because the measurements differ, the number of units and standard drinks in a beverage can vary.

A large (250ml) glass of 12% ABV wine contains about 3 units of alcohol. This is a common example where a single serving can exceed recommended daily intake for some guidelines.

No, health guidelines advise against saving up your units for a single heavy drinking session, which is known as binge drinking. This can cause significant short-term and long-term harm to your body.

Yes. A person with a lower body weight will generally have a higher blood alcohol concentration (BAC) than a heavier person who consumes the same amount of alcohol, meaning the effects will be felt more intensely.

Guidelines vary by region. In the UK, the 14 units per week guideline applies to both men and women. In the US, separate recommendations are provided, with lower weekly limits for women.

On average, it takes an adult about one hour to process one UK unit of alcohol, but this can vary depending on individual factors such as metabolism and body weight.

Regularly exceeding recommended unit limits can lead to severe health problems over time, including liver damage, various cancers (mouth, throat, breast), stroke, and heart disease.