Unit tracker
Alcohol Unit Calculator: How Many Units Have You Had?
Calculate units for any drink using volume and ABV, with support for UK units, Australian standard drinks, US standard drinks, Canadian standard drinks, WHO units, and weekly guideline tracking.
UK unit
8g pure alcohol
About 25ml of 40% spirits, or one third of a pint of 5% beer
UK weekly guideline
14 units
For both men and women under the UK Chief Medical Officers' guideline
A pint of 5% lager
2.8 units
One of the most common UK unit miscalculations
Reference only
This calculator uses a Widmark-style formula for estimation only. Individual results vary based on metabolism, food intake, medications, health, and drink accuracy. Never use this tool to decide whether you are safe to drive, work, or perform safety-critical tasks.
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Calculate Units for a Drink, Session, or Week
Switch the unit system first, then calculate a single drink, a full session, or this week's total against the selected guideline.
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1x Pint lager (568ml)
🇬🇧 2.8 units
- Pure alcohol
- 22.4g
- Alcohol calories
- ~157 kcal
Want to know your BAC?
Units measure total alcohol consumed. BAC estimates how that alcohol may affect your blood alcohol level right now, using weight, sex, and timing.
Calculate BAC for these drinksQuick reference
Units at a Glance: Common Drinks Reference
The table below shows common drinks and serving sizes. Your selected system is 🇬🇧 UK units, with UK, Australian, and US equivalents shown side by side.
| Drink | Serving | ABV | UK Units | AU Std | US Std | Selected | |
|---|---|---|---|---|---|---|---|
| Bottle of wine | 750ml | 13.0% | 9.6 | 7.7 | 5.5 | 9.6 units | 76.9g |
| Strong cider can | 500ml | 7.5% | 3.7 | 3.0 | 2.1 | 3.7 units | 29.6g |
| Pint of strong lager | 568ml | 6.5% | 3.6 | 2.9 | 2.1 | 3.6 units | 29.1g |
| Large glass of wine | 250ml | 13.0% | 3.2 | 2.6 | 1.8 | 3.2 units | 25.6g |
| Pint of lager | 568ml | 5.0% | 2.8 | 2.2 | 1.6 | 2.8 units | 22.4g |
| Pint of cider | 568ml | 4.5% | 2.5 | 2.0 | 1.4 | 2.5 units | 20.2g |
| Standard glass of wine | 175ml | 13.0% | 2.2 | 1.8 | 1.3 | 2.2 units | 17.9g |
| Double spirit | 50ml | 40.0% | 2.0 | 1.6 | 1.1 | 2.0 units | 15.8g |
| Can of cider | 440ml | 4.5% | 2.0 | 1.6 | 1.1 | 2.0 units | 15.6g |
| Single spirit (US/AU) | 44ml | 40.0% | 1.7 | 1.4 | 1.0 | 1.7 units | 13.9g |
| Can of lager | 330ml | 5.0% | 1.6 | 1.3 | 0.9 | 1.6 units | 13.0g |
| Bottle of beer | 330ml | 5.0% | 1.6 | 1.3 | 0.9 | 1.6 units | 13.0g |
| Small glass of wine | 125ml | 13.0% | 1.6 | 1.3 | 0.9 | 1.6 units | 12.8g |
| Champagne flute | 125ml | 12.0% | 1.5 | 1.2 | 0.8 | 1.5 units | 11.8g |
| Half pint of lager | 284ml | 5.0% | 1.4 | 1.1 | 0.8 | 1.4 units | 11.2g |
| Alcopop / RTD | 275ml | 5.0% | 1.4 | 1.1 | 0.8 | 1.4 units | 10.8g |
| Single spirit (UK) | 25ml | 40.0% | 1.0 | 0.8 | 0.6 | 1.0 units | 7.9g |
UK units can also be approximated as volume (ml) x ABV (%) / 1,000. For a full database of drinks and ABV values, see the alcohol content by drink guide.
Section 1
The UK Unit System: What It Is and How to Use It
A UK unit of alcohol contains 8 grams of pure ethanol. The common UK formula is volume (ml) x ABV (%) / 1,000. A 568ml pint of 5% lager is 568 x 5 / 1,000 = 2.84 units. A 175ml glass of 13% wine is 2.275 units. A 25ml measure of 40% spirits is 1 unit.
For a deeper country-by-country converter, see the drink standard units calculator. The important point is that one drink does not usually equal one unit. A pint of modern lager contains almost three UK units.
The UK Chief Medical Officers' low-risk guideline recommends no more than 14 units per week for both men and women, spread across at least three days with several alcohol-free days. This replaced the older 21-unit male guideline. It is a maximum for lower-risk drinking, not a target.
Section 2
Weekly Drinking Guidelines: UK vs Australia vs USA
Because standard drink sizes differ between countries, weekly guidelines expressed in units or standard drinks represent different amounts of pure alcohol. This matters for health planning, alcohol and weight loss, and long-term intake tracking.
| Country | System | Weekly limit (women) | Pure alcohol | Weekly limit (men) | Pure alcohol |
|---|---|---|---|---|---|
| 🇬🇧 UK | Units (8g) | 14 units | 112g | 14 units | 112g |
| 🇦🇺 Australia | Std drinks (10g) | 10 drinks | 100g | 10 drinks | 100g |
| 🇺🇸 USA | Std drinks (14g) | 7 drinks | 98g | 14 drinks | 196g |
| 🇨🇦 Canada | Std drinks (13.6g) | 10 drinks | 136g | 15 drinks | 204g |
| 🇳🇿 New Zealand | Std drinks (10g) | 10 drinks | 100g | 15 drinks | 150g |
| 🇫🇷 France | Std drinks (10g) | 10 drinks | 100g | 10 drinks | 100g |
| 🇳🇱 Netherlands | Std drinks (10g) | 7 drinks | 70g | 7 drinks | 70g |
The Netherlands has one of the most restrictive guideline positions in pure alcohol terms, while US guidance permits more alcohol for men than the UK guideline. For full definitions, see standard drink sizes by country.
Section 3
Units vs BAC: What Each Measurement Tells You
Units measure total alcohol consumed. BAC measures the concentration of alcohol in your blood at a specific moment. Units are useful for weekly health tracking; BAC is the relevant measure for impairment, immediate safety, and driving risk. For the mechanics, see how BAC works.
The same number of units can produce very different BAC levels depending on drinking speed, body weight, sex, food, and elapsed time. Eight units over eight hours is not the same immediate impairment risk as eight units over two hours.
Use units for long-term intake tracking. Use the BAC calculator or drink drive calculator when the question is current impairment or driving safety.
Section 4
Why Tracking Your Units Actually Reduces How Much You Drink
Tracking works because most people underestimate their alcohol intake. Seeing the unit count as a percentage of the weekly guideline makes the abstract idea of "how much I had" concrete. For many people, that feedback alone reduces intake.
The weekly tracker above stores entries in your browser only and resets when the week changes. If you are intentionally reducing intake, lower-strength choices can help. See the low alcohol drinks guide for practical substitution strategies.
Related pages
Convert units into context
BAC Calculator
Convert your unit count into a blood alcohol concentration estimate, accounting for weight, sex, and drinking pace.
Standard Drink Sizes by Country
Why a UK unit, Australian standard drink, and US standard drink are not the same, and how to convert between them.
Alcohol Content by Drink
ABV database for 200+ drinks with serving sizes, alcohol grams, and standard-drink context.
Low Alcohol Drinks Guide
How switching to lower-ABV drinks reduces your unit count, with scenario-based recommendations.
FAQ
Alcohol Unit Calculator FAQ
Common questions about UK alcohol units, weekly guidelines, standard drinks, wine servings, beer pints, and how units differ from BAC.
For UK units, use volume in millilitres multiplied by ABV percentage, divided by 1,000. A 568ml pint of 5% lager is 568 x 5 / 1,000 = 2.84 units. The calculator above does the same conversion and can also show Australian, US, Canadian, and WHO-style units.
It depends on the ABV. A pint of 4% lager is about 2.3 UK units, a pint of 5% lager is about 2.8 units, and a pint of 6% IPA is about 3.4 units. The assumption that one pint equals one unit is wrong for modern beer strengths.
The UK low-risk guideline is no more than 14 units per week for both men and women, spread across several days with alcohol-free days. It is not a risk-free threshold or target; it is a recommended maximum above which health risk rises.
A 750ml bottle of wine at 13% ABV is about 9.75 UK units using the simple unit formula. At 14% ABV it is about 10.5 units, which is roughly three quarters of the UK weekly guideline in one bottle.
A 125ml glass of 13% wine is about 1.6 UK units. A 175ml glass is about 2.3 units. A 250ml large glass is about 3.3 units. The glass size matters as much as the ABV.
They are different measurement systems for pure alcohol. A UK unit is 8g of pure alcohol. An Australian or WHO standard drink is 10g. A US standard drink is 14g. A Canadian standard drink is about 13.6g. Use the country selector above to convert the same drink between systems.